Time filter

Source Type

Patent
Corning Inc. and CAS Dalian Institute of Chemical Physics | Date: 2016-11-10

Extruded honeycomb catalyst bodies and methods of manufacturing same. The catalyst body includes a first oxide selected from the group consisting of tungsten oxides, vanadium oxides, and combinations thereof, a second oxide selected from the group consisting of cerium oxides, lanthanum oxides, zirconium oxides, and combinations thereof, and a zeolite.


Patent
CAS Dalian Institute of Chemical Physics | Date: 2017-04-12

This invention relates to a method for preparing p-xylene and co-producing propylene with a high selectivity. Toluene and methanol and/or dimethyl ether as raw materials are brought into contact with a catalyst in a reaction system for reaction, and after the resultant product is separated via a separation system, an ethylene-enriched C_(2)^(-) component (hydrocarbons having carbon number less than or equal to 2, CO, CO_(2), and H_(2)) therein is returned to the reaction system for further reaction, a C_(6)^(+) component (aromatic hydrocarbons having carbon number greater than or equal to 6) is subjected to further separation to obtain p-xylene, and a C_(3) component (propylene and propane having a carbon number equal to 3) is subjected to further separation to obtain propylene. This method prepares p-xylene and co-produces propylene with a high selectivity, by coupling two reaction processes, an alkylation reaction of toluene with methanol and/or dimethyl ether and an alkylation reaction of ethylene with methanol and/or dimethyl ether, recycling an ethylene-enriched C_(2)^(-) component in reaction byproducts of alkylation of toluene and methanol and/or dimethyl ether, and performing alkylation reaction with methanol and/or dimethyl ether in the presence of catalysts.


Patent
CAS Dalian Institute of Chemical Physics | Date: 2017-04-12

This invention relates to a method for preparing p-xylene and propylene from methanol and/or dimethyl ether. This method comprises coupling two reaction processes, an aromatization reaction of methanol and/or dimethyl ether and an alkylation reaction of ethylene with methanol and/or dimethyl ether. The method of this invention produces p-xylene and propylene with a high selectivity by returning an ethylene-enriched component in reaction byproducts from preparation of p-xylene from methanol and/or dimethyl ether to the reaction system for performing alkylation reaction with methanol and/or dimethyl ether in the presence of catalysts.


Wang L.Z.,Hubei University for Nationalities | Duan Z.C.,Hubei University for Nationalities | Liang X.M.,CAS Dalian Institute of Chemical Physics
International Journal of Environmental Research | Year: 2017

A simple and robust eradication process for chlorophenols in natural seawater under natural conditions, i.e., sunlight irradiation, air, was developed. It demonstrated that non-biological environmental factors, air and natural sunlight can lead to efficient degradation of chlorophenols [2,4,6-trichlorophenol (TCP), 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP)] in the seawater without any biological factors participating. It is noteworthy that the industrial effluents of 2,4-dichlorophenoxyacetic acid (2,4-D) production which contain some chlorophenols and unknown compounds were also degraded efficiently. Typically, a set amount of TCP was dissolved in 15 mL of seawater, previously passed through 0.45 μm filter to remove solid impurity in a test glass tube and placed out-of-doors under direct sunlight for a set period of time. It was shown that more than 99.3% of 2,4,6-trichlorophenol (TCP) in the seawater were removed with only 9 h incubating, without agitation out of the door, and the removal of total organic carbon (TOC) was higher than 83% after sunlight irradiation for 20 days. Our results suggest that inorganic feature environment factors will need to be included in future modeling studies for the environment self-degradation of pollutants. © 2017, University of Tehran.


Liu J.,CAS Dalian Institute of Chemical Physics | Liu J.,China University of Petroleum - East China | Leng J.,CAS Dalian Institute of Chemical Physics | Wu K.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of the American Chemical Society | Year: 2017

Two-dimensional (2D) organolead halide perovskites are promising for various optoelectronic applications. Here we report a unique spontaneous charge (electron/hole) separation property in multilayered (BA)2(MA)n-1PbnI3n+1 (BA = CH3(CH2)3NH3 +, MA = CH3NH3 +) 2D perovskite films by studying the charge carrier dynamics using ultrafast transient absorption and photoluminescence spectroscopy. Surprisingly, the 2D perovskite films, although nominally prepared as "n = 4", are found to be mixture of multiple perovskite phases, with n = 2, 3, 4 and ≈ ∞, that naturally align in the order of n along the direction perpendicular to the substrate. Driven by the band alignment between 2D perovskites phases, we observe consecutive photoinduced electron transfer from small-n to large-n phases and hole transfer in the opposite direction on hundreds of picoseconds inside the 2D film of ∼358 nm thickness. This internal charge transfer efficiently separates electrons and holes to the upper and bottom surfaces of the films, which is a unique property beneficial for applications in photovoltaics and other optoelectronics devices. © 2017 American Chemical Society.


Liang G.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | Li L.,CAS Dalian Institute of Chemical Physics | Xu G.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2017

Transformation of biomass into valuable nitrogen-containing compounds is highly desired, yet limited success has been achieved. Here we report an efficient catalyst system, partially reduced Ru/ZrO2, which could catalyze the reductive amination of a variety of biomass-derived aldehydes/ketones in aqueous ammonia. With this approach, a spectrum of renewable primary amines was produced in good to excellent yields. Moreover, we have demonstrated a two-step approach for production of ethanolamine, a large-market nitrogen-containing chemical, from lignocellulose in an overall yield of 10 %. Extensive characterizations showed that Ru/ZrO2-containing multivalence Ru association species worked as a bifunctional catalyst, with RuO2 as acidic promoter to facilitate the activation of carbonyl groups and Ru as active sites for the subsequent imine hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


Wu B.,CAS Dalian Institute of Chemical Physics | Yu Z.,Chongqing University | Gao X.,CAS Dalian Institute of Chemical Physics | Lan Y.,Chongqing University | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Angewandte Chemie - International Edition | Year: 2017

The enantioselective α-addition of deconjugated butenolides has rarely been exploited, in contrast to the well-studied γ-addition of deconjugated butenolides. In this study, an unprecedented asymmetric α-addition/transesterification of deconjugated butenolides with ortho-quinone methides generated in situ afforded a series of functionalized 3,4-dihydrocoumarins containing two contiguous stereogenic centers with excellent diastereo- and enantioselectivity. DFT calculations suggested that the rarely observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic dienolate and the electrophilic ortho-quinone methide. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


Jiang B.,CAS Dalian Institute of Chemical Physics | Wu Q.,CAS Dalian Institute of Chemical Physics | Wu Q.,University of Chinese Academy of Sciences | Zhang L.,CAS Dalian Institute of Chemical Physics | Zhang Y.,CAS Dalian Institute of Chemical Physics
Nanoscale | Year: 2017

Although selective enrichment of glycopeptides from complex biological samples is indispensable for mass spectrometry (MS)-based glycoproteomics, it still remains a great challenge due to the low abundance of glycoproteins and suppression of non-glycopeptides. In this study, silver nanoparticle-functionalized magnetic graphene oxide nanocomposites (GO/Fe3O4/PEI/Ag) were synthesized. Silver nanoparticles were generated in situ on the surface of magnetic graphene oxide using polyethylenimine as a reducing and stabilizing agent. The resulting material was used as an adsorbent for selective enrichment of glycopeptides. GO/Fe3O4/PEI/Ag nanocomposites offered excellent enrichment ability, which was attributed to the synergistic effect of polyethylenimine and silver nanoparticles. The nanocomposites showed superior specificity for glycopeptides even when non-glycopeptides were 100 times more concentrated than glycopeptides. The nanocomposites displayed advantages including rapid adsorption (1 min), low detection limit (25 fmol), repeatability (6 times), and high recovery (77.8%). Using these nanocomposites, 91 different glycoproteins and 136 N-linked glycopeptides were identified from among 20 μg tryptic human serum proteins and this demonstrated the superior performance of the nanocomposites for glycopeptides enrichment. © 2017 The Royal Society of Chemistry.


Guo W.,CAS Dalian Institute of Chemical Physics | Liu Y.,CAS Dalian Institute of Chemical Physics | Li C.,CAS Dalian Institute of Chemical Physics
Organic Letters | Year: 2017

The first enantioselective catalytic 1,2-hydroperoxidation has been achieved in the presence of PEG-600 using an acid-base bifunctional chiral squaramide as the organocatalyst, affording a range of enantioenriched α-N-substituted hydroperoxides bearing an oxindole moiety with excellent stereoselectivities (up to 99% ee). © 2017 American Chemical Society.


Li R.,Dalian National Laboratory for Clean Energy | Li R.,CAS Dalian Institute of Chemical Physics
Chinese Journal of Catalysis | Year: 2017

Hydrogen production via solar water splitting is regarded as one of the most promising ways to utilize solar energy and has attracted more and more attention. Great progress has been made on photocatalytic water splitting for hydrogen production in the past few years. This review summarizes the very recent progress (mainly in the last 2–3 years) on three major types of solar hydrogen production systems: particulate photocatalysis (PC) systems, photoelectrochemical (PEC) systems, and photovoltaic-photoelectrochemical (PV-PEC) hybrid systems. The solar-to-hydrogen (STH) conversion efficiency of PC systems has recently exceeded 1.0% using a SrTiO3:La,Rh/Au/BiVO4:Mo photocatalyst, 2.5% for PEC water splitting on a tantalum nitride photoanode, and reached 22.4% for PV-PEC water splitting using a multi-junction GaInP/GaAs/Ge cell and Ni electrode hybrid system. The advantages and disadvantages of these systems for hydrogen production via solar water splitting, especially for their potential demonstration and application in the future, are briefly described and discussed. Finally, the challenges and opportunities for solar water splitting solutions are also forecasted. © 2017 Dalian Institute of Chemical Physics, the Chinese Academy of Sciences


Chen S.,Messina University | Perathoner S.,Messina University | Ampelli C.,Messina University | Mebrahtu C.,Messina University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2017

Ammonia is synthesized directly from water and N2 at room temperature and atmospheric pressure in a flow electrochemical cell operating in gas phase (half-cell for the NH3 synthesis). Iron supported on carbon nanotubes (CNTs) was used as the electrocatalyst in this half-cell. A rate of ammonia formation of 2.2×10-3gNH3 m-2h-1 was obtained at room temperature and atmospheric pressure in a flow of N2, with stable behavior for at least 60h of reaction, under an applied potential of -2.0V. This value is higher than the rate of ammonia formation obtained using noble metals (Ru/C) under comparable reaction conditions. Furthermore, hydrogen gas with a total Faraday efficiency as high as 95.1% was obtained. Data also indicate that the active sites in NH3 electrocatalytic synthesis may be associated to specific carbon sites formed at the interface between iron particles and CNT and able to activate N2, making it more reactive towards hydrogenation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Cao X.,Nanjing University of Science and Technology | Jiang S.,Nanjing University of Science and Technology | Yu C.,Nanjing University of Science and Technology | Wang Y.,Nanjing University of Science and Technology | And 3 more authors.
Optics Express | Year: 2014

We present a theoretical investigation of high-order harmonic generation in spatially inhomogeneous two-color laser fields by solving three dimensional time dependent Schrödinger equation. The cutoff in the harmonic spectra can be significantly extended by means of our proposed method (i.e., from helium interacting with the plasmon-enhanced two-color laser fields), and an ultrabroad supercontinuum up to 1.5 keV is generated by selecting proper carrier-envelope phase of the controlling field. Moreover, classical trajectory extraction, time-dependent ionization and recombination rates, and time-frequency analyses are used to explain the generation of this ultrabroadband supercontinuum. As a result, an isolated 8.8 attosecond pulse can be generated directly by the superposition of the supercontinuum harmonics. © 2014 Optical Society of America.


Chua Y.S.,CAS Dalian Institute of Chemical Physics | Li W.,CAS Dalian Institute of Chemical Physics | Li W.,National University of Singapore | Wu G.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemistry of Materials | Year: 2012

Metal amidoborane ammoniate such as Mg(NH 2BH 3) 2•NH 3 and Ca(NH 2BH 3) 2•nNH 3 with n = 1, 2, release NH 3 predominantly and endothermically at low temperatures in an open-system. However, a strong exothermic reaction occurs when these ammoniates were dehydrogenated in a closed-system, where the adducted NH 3 take part in the reaction. Our approach in tailoring the thermodynamic properties of Mg(NH 2BH 3) 2•NH 3, by replacing its adducted NH 3 with amide was successful, yielding a composite consisting of bimetallic amidoborane and Mg(NH 2) 2. Crystal structures of bimetallic amidoboranes, i.e., Na 2Mg(NH 2BH 3) 4 and K 2Mg(NH 2BH 3) 4 were identified and solved. Significant improvement in the dehydrogenation thermodynamic was observed in the composite system as compared to the pristine Mg(NH 2BH 3) 2•NH 3, i.e., the dehydrogenation enthalpies were altered from an exothermic to an endothermic one. In addition, the detection of bimetallic amidoboranes in the composites urges detailed investigation on pristine bimetallic amidoborane, to which later we found that Na 2Mg(NH 2BH 3) 4 also dehydrogenated endothermically at the identical temperature range (ca. 150-170 °C) with that of composite systems. Similar activation barriers were observed in Na 2Mg(NH 2BH 3) 4 and composite systems, suggesting that metal hydride mediation may be the internal barrier that dominates the kinetic barrier of the composite system. First-principles calculations also showed that the thermodynamic stability of metal amidoborane (MNH 2BH 3, MAB) increases with decreasing Pauling electronegativity of the metal. Based on the calculated results, a reactant stabilization approach was proposed, which suggests that forming a stable reactant is an effective way of reducing the exothermicity of the dehydrogenation of metal amidoborane. © 2012 American Chemical Society.


Gao X.,CAS Dalian Institute of Chemical Physics | Wu B.,CAS Dalian Institute of Chemical Physics | Huang W.-X.,CAS Dalian Institute of Chemical Physics | Chen M.-W.,CAS Dalian Institute of Chemical Physics | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Angewandte Chemie - International Edition | Year: 2015

A palladium-catalyzed enantioselective C-H functionalization of indoles was achieved with an axially chiral 2,2′-bipyridine ligand, thus providing the desired indol-3-acetate derivatives with up to 98 % ee. Moreover, the reaction protocol was also effective for asymmetric O-H insertion reaction of phenols using α-aryl-α-diazoacetates. This represents the first successful application of bipyridine ligands with axial chirality in palladium-catalyzed carbene migratory insertion reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang X.,Dalian University of Technology | Liu Y.,Dalian University of Technology | Li S.,Dalian University of Technology | Kong L.,Dalian University of Technology | And 7 more authors.
Chemistry of Materials | Year: 2014

A new ZIF-8 membrane architecture with high performance supported on vertically aligned ZnO nanorods was successfully prepared. The vertically aligned, single crystal ZnO nanorods were grown seamlessly from porous ceramic support to form an intermediate support layer for the ZIF-8 membrane. They provide multiple anchorages for the ZIF-8 membrane that are both strong and flexible. The nanorods were activated to induce a uniform nucleation of ZIF nuclei on their surface to initiate and guide the growth of a defect-free ZIF-8 membrane. Single gas permeations and binary separations carried out to investigate the transport properties of these new membrane architectures confirmed that the ZIF-8 membranes were free of defects and stable at a higher temperature (473 K). © 2014 American Chemical Society.


Chen Z.-P.,CAS Dalian Institute of Chemical Physics | Chen M.-W.,CAS Dalian Institute of Chemical Physics | Shi L.,CAS Dalian Institute of Chemical Physics | Yu C.-B.,CAS Dalian Institute of Chemical Physics | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Chemical Science | Year: 2015

An efficient palladium-catalyzed asymmetric hydrogenation of fluorinated aromatic pyrazol-5-ols has been developed via capture of the active tautomers. A wide variety of 2,5-disubstituted and 2,4,5-trisubstituted pyrazolidinones have been synthesized with up to 96% and 95% ee, respectively. The hydrogenation pathway includes Brønsted acid promoted tautomerization of pyrazol-5-ols and Pd-catalyzed asymmetric hydrogenation of the active tautomer. This journal is © The Royal Society of Chemistry.


Xu C.,CAS Dalian Institute of Chemical Physics | Xu C.,Dalian University of Technology | Yang W.,CAS Dalian Institute of Chemical Physics | Ren Z.,Peking University | And 5 more authors.
Journal of the American Chemical Society | Year: 2013

Photocatalytic dissociation of methanol (CH3OH) on a TiO 2(110) surface has been studied by temperature programmed desorption (TPD) at 355 and 266 nm. Primary dissociation products, CH2O and H atoms, have been detected. The dependence of the reactant and product TPD signals on irradiation time has been measured, allowing the photocatalytic reaction rate of CH3OH at both wavelengths to be directly determined. The initial dissociation rate of CH3OH at 266 nm is nearly 2 orders of magnitude faster than that at 355 nm, suggesting that CH3OH photocatalysis is strongly dependent on photon energy. This experimental result raises doubt about the widely accepted photocatalysis model on TiO2, which assumes that the excess potential energy of charge carriers is lost to the lattice via strong coupling with phonon modes by very fast thermalization and the reaction of the adsorbate is thus only dependent on the number of electron-hole pairs created by photoexcitation. © 2013 American Chemical Society.


Hua Q.,Suzhou University of Science and Technology | Cao T.,Suzhou University of Science and Technology | Gu X.-K.,CAS Dalian Institute of Chemical Physics | Lu J.,Zhejiang Normal University | And 5 more authors.
Angewandte Chemie - International Edition | Year: 2014

The selective oxidation of propylene with O2 to propylene oxide and acrolein is of great interest and importance. We report the crystal-plane-controlled selectivity of uniform capping-ligand-free Cu 2O octahedra, cubes, and rhombic dodecahedra in catalyzing propylene oxidation with O2: Cu2O octahedra exposing {111} crystal planes are most selective for acrolein; Cu2O cubes exposing {100} crystal planes are most selective for CO2; Cu2O rhombic dodecahedra exposing {110} crystal planes are most selective for propylene oxide. One-coordinated Cu on Cu2O(111), three-coordinated O on Cu2O(110), and two-coordinated O on Cu2O(100) were identified as the catalytically active sites for the production of acrolein, propylene oxide, and CO2, respectively. These results reveal that crystal-plane engineering of oxide catalysts could be a useful strategy for developing selective catalysts and for gaining fundamental understanding of complex heterogeneous catalytic reactions at the molecular level. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chua Y.S.,National University of Singapore | Chen P.,CAS Dalian Institute of Chemical Physics | Wu G.,CAS Dalian Institute of Chemical Physics | Xiong Z.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2011

With high hydrogen content and moderate dehydrogenation conditions, metal amidoboranes have been regarded as potential hydrogen storage candidates and have attracted increasing attention recently. In this review we provide a practical introduction to the recent progress on the syntheses, crystal structures and dehydrogenation properties of metal amidoboranes and their derivatives. © 2011 The Royal Society of Chemistry.


Xing W.,Shandong University of Technology | Liu C.,Shandong University of Technology | Zhou Z.,Shandong University of Technology | Zhang L.,CAS Dalian Institute of Chemical Physics | And 6 more authors.
Energy and Environmental Science | Year: 2012

Here we show that the introduction of N into a carbon surface facilitates the hydrogen-bonding interactions between the carbon surface and CO2 molecules, which accounts for the superior CO2 uptake of the N-doped activated carbons. This new finding challenges the long-held viewpoint that acid-base interactions between N-containing basic functional groups and acidic CO2 gas are responsible for the enhanced CO2 capture capacity of N-doped carbons. This journal is © 2012 The Royal Society of Chemistry.


Wang N.,University of Sichuan | Chu W.,University of Sichuan | Zhang T.,CAS Dalian Institute of Chemical Physics | Zhao X.S.,National University of Singapore
International Journal of Hydrogen Energy | Year: 2012

A series of Ce-incorporated SBA-15 mesoporous materials were synthesized through direct hydrothermal synthesis method and further impregnated with 12 wt.% Ni. The samples were characterized by ICP-AES, XRD, N 2 physisorption, XPS, TPR, H 2 chemisorption, TGA, temperature- programmed hydrogenation (TPH) and TEM measurements. The low-angle XRD and N 2 physisorption results showed the Ce successfully incorporated into the framework of SBA-15. The catalytic properties of these catalysts were investigated in methane reforming with CO 2. The Ce/Si molar ratio had a significant influence on the catalytic performance. The highest catalytic activity and long-term stability were obtained over the Ni/Ce-SBA-15 (Ce/Si = 0.04) sample. The improved catalytic behavior could be attributed to the cerium impact in the framework of SBA-15, where cerium promoted the dispersion of nano-sized Ni species and inhibited the carbon formation. In comparison with the effect of CeO 2 crystallites in SBA-15, cerium in the framework of SBA-15 promoted the formation of the nickel metallic particles with smaller size. The XRD and TGA results exhibited that carbon deposition was responsible for activity loss of Ni/SBA-15 and Ni/Ce-SBA-15 (Ce/Si = 0.06) catalysts. TEM results showed that the hexagonal mesopores of SBA-15 were still kept intact after reaction and the pore walls of SBA-15 prevented the aggregation of nickel. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Liu Y.,CAS Dalian Institute of Chemical Physics | Liu Y.,Zhejiang Normal University | Zhen W.,CAS Dalian Institute of Chemical Physics | Dai W.,Zhejiang Normal University | And 2 more authors.
Organic Letters | Year: 2013

AgOTf can catalyze an addition-cyclization tandem between alkyne-azomethine and a nucleophile such as ketone, nitroalkane, water, and terminal alkyne to give a polycyclic amide via six-exo-trig selectivity. © 2013 American Chemical Society.


Gao L.,CAS Shenyang Institute of Metal Research | Ren W.,CAS Shenyang Institute of Metal Research | Xu H.,Peking University | Jin L.,CAS Dalian Institute of Chemical Physics | And 8 more authors.
Nature Communications | Year: 2012

Large single-crystal graphene is highly desired and important for the applications of graphene in electronics, as grain boundaries between graphene grains markedly degrade its quality and properties. Here we report the growth of millimetre-sized hexagonal single-crystal graphene and graphene films joined from such grains on Pt by ambient-pressure chemical vapour deposition. We report a bubbling method to transfer these single graphene grains and graphene films to arbitrary substrate, which is nondestructive not only to graphene, but also to the Pt substrates. The Pt substrates can be repeatedly used for graphene growth. The graphene shows high crystal quality with the reported lowest wrinkle height of 0.8 nm and a carrier mobility of greater than 7,100 cm2 V-1 s-1 under ambient conditions. The repeatable growth of graphene with large single-crystal grains on Pt and its nondestructive transfer may enable various applications. © 2012 Macmillan Publishers Limited. All rights reserved.


Shen Z.,Tongji University | Shen Z.,CAS Dalian Institute of Chemical Physics | Zhang Y.,Tongji University | Jin F.,Shanghai JiaoTong University
RSC Advances | Year: 2012

A hydrothermal method for the hydrogen-transfer reduction of CO 2 or NaHCO 3 is presented. This process uses glycerine as a reducing agent, which is ultimately converted to lactate, and can convert NaHCO 3 into formate in about a 90% yield with respect to the initial amount of glycerine. © 2012 The Royal Society of Chemistry.


Li L.,KTH Royal Institute of Technology | Duan L.,KTH Royal Institute of Technology | Wen F.,CAS Dalian Institute of Chemical Physics | Li C.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
Chemical Communications | Year: 2012

A molecular device with a photocathode for hydrogen generation has been successfully demonstrated, based on an earth abundant and inexpensive p-type semiconductor NiO, an organic dye P1 and a cobalt catalyst Co1. © 2012 The Royal Society of Chemistry.


Mudiyanselage K.,Brookhaven National Laboratory | An W.,Brookhaven National Laboratory | Yang F.,Brookhaven National Laboratory | Yang F.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2013

In this study the identity of diverse adsorption sites on a 5-7 Cu 2O/Cu(111) surface oxide structure has been identified. The 5-7 membered rings formed by a topological defect on stoichiometric Cu2O present different electronic structures from the originating hexagonal rings, as shown by combined bias dependent scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The adsorption of CO as a probe molecule on the 5-7 structure, studied using infrared reflection-absorption spectroscopy (IRRAS), shows the existence of special adsorption sites. By combining experimental and theoretical results, it is determined that CO molecules can be selectively confined inside the 7-membered oxide rings with internal dimensions of ∼0.85 nm, leading to a marked different adsorbate-substrate interaction than in either clean Cu(111) or Cu2O. The implication of these newly discovered sites on the chemistry of copper for catalytic reactions is discussed. © 2013 the Owner Societies.


Li F.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Johansson B.,Dalian University of Technology | Johansson B.,KTH Royal Institute of Technology | Sun L.,CAS Dalian Institute of Chemical Physics
International Journal of Hydrogen Energy | Year: 2010

We proposed a possible way of promoting the binding of H2 molecules on covalent organic frameworks crystals via substituting the bridge C2O2B rings with different metal-participated rings, which can naturally avoid the clustering of metal atoms. First-principles calculations on both crystalline phase and molecular fragments show that the H2 binding energy can be enhanced by a factor of four with regard to the undoped crystal, i.e. reaching about 10 kJ/mol. Grand canonical Monte Carlo simulations further confirm that such substitutional doping would improve the room temperature hydrogen storage capacity by a factor of two to three. © 2009 Professor T. Nejat Veziroglu.


Hou J.,Virginia Polytechnic Institute and State University | Shao Y.,Pacific Northwest National Laboratory | Ellis M.W.,Virginia Polytechnic Institute and State University | Moore R.B.,Virginia Polytechnic Institute and State University | Yi B.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

Graphene has attracted extensive research interest due to its strictly 2-dimensional (2D) structure, which results in its unique electronic, thermal, mechanical, and chemical properties and potential technical applications. These remarkable characteristics of graphene, along with the inherent benefits of a carbon material, make it a promising candidate for application in electrochemical energy devices. This article reviews the methods of graphene preparation, introduces the unique electrochemical behavior of graphene, and summarizes the recent research and development on graphene-based fuel cells, supercapacitors and lithium ion batteries. In addition, promising areas are identified for the future development of graphene-based materials in electrochemical energy conversion and storage systems. This journal is © the Owner Societies.


Chen J.-S.,CAS Dalian Institute of Chemical Physics | Chen J.-S.,University of Chinese Academy of Sciences | Zhou P.-W.,CAS Dalian Institute of Chemical Physics | Li G.-Y.,Hebei United University | And 3 more authors.
Journal of Physical Chemistry B | Year: 2013

The fluoride anion sensing mechanism of 6-methyl-5-(9-methylene-anthracene) -(2-butylureido-4[1H]-pyrimidinone) (AnUP) has been investigated using the DFT/TDDFT method. The theoretical results indicate that the proton of the N 3-H3 group in pyrimidine moiety is captured by the added fluoride anion and then deprotonated. The calculated vertical excitation energies of AnUP-dimer and its deprotonated form agree well with the experimental results. The molecular orbital analysis demonstrates that the first excited state (S1) of AnUP-dimer is a local excited state with a π-π* transition, whereas for the deprotonated form, S1 is a completely charge-separation state and is responsible for the photoinduced electron transfer (PET) process. The PET process from anthracene to the pyrimidine moiety leads to the fluorescence quenching. © 2013 American Chemical Society.


Vijayakumar M.,Pacific Northwest National Laboratory | Li L.,Pacific Northwest National Laboratory | Graff G.,Pacific Northwest National Laboratory | Liu J.,Pacific Northwest National Laboratory | And 3 more authors.
Journal of Power Sources | Year: 2011

The V5+ electrolyte solution from Vanadium Redox Flow Batteries was studied by variable temperature 17O and 51V Nuclear Magnetic Resonance (NMR) spectroscopy and density functional theory (DFT) based computational modeling. It was found that the V5+ species exist as hydrated penta co-ordinated vanadate ion, i.e. [VO2(H 2O)3]1+. This hydrated structure is not stable at elevated temperature and change into neutral H3VO4 molecule via a deprotonation process and subsequently leading to the observed V2O5 precipitation in V5+ electrolyte solutions. © 2010 Elsevier B.V. All rights reserved.


Deng D.,CAS Dalian Institute of Chemical Physics | Pan X.,CAS Dalian Institute of Chemical Physics | Yu L.,CAS Dalian Institute of Chemical Physics | Cui Y.,CAS Dalian Institute of Chemical Physics | And 8 more authors.
Chemistry of Materials | Year: 2011

Theoretical studies predicted that doping graphene with nitrogen can tailor its electronic properties and chemical reactivity. However, experimental investigations are still limited because of the lack of synthesis techniques that can deliver a reasonable quantity. We develop here a novel method for one-pot direct synthesis of N-doped graphene via the reaction of tetrachloromethane with lithium nitride under mild conditions, which renders fabrication in gram scale. The distinct electronic structure perturbation induced by the incorporation of nitrogen in the graphene network is observed for the first time by scanning tunnelling microscopy. The nitrogen content varies in the range of 4.5-16.4%, which allows further modulation of the properties. The enhanced catalytic activity is demonstrated in a fuel cell cathode oxygen reduction reaction with respect to pure graphene and commercial carbon black XC-72. The resulting N-doped materials are expected to broaden the already widely explored potential applications for graphene.(Figure Presented) © 2011 American Chemical Society.


Wang N.,Dalian University of Technology | Wang N.,Henan University of Technology | Wang M.,Dalian University of Technology | Wang Y.,KTH Royal Institute of Technology | And 5 more authors.
Journal of the American Chemical Society | Year: 2013

A [FeFe]-hydrogenase model (1) containing a chelating diphosphine ligand with a pendant amine was readily oxidized by Fc+ (Fc = Cp 2Fe) to a FeIIFeI complex ([1]+), which was isolated at room temperature. The structure of [1]+ with a semibridging CO and a vacant apical site was determined by X-ray crystallography. Complex [1]+ catalytically activates H2 at 1 atm at 25 C in the presence of excess Fc+ and P(o-tol) 3. More interestingly, the catalytic activity of [1]+ for H2 oxidation remains unchanged in the presence of ca. 2% CO. A computational study of the reaction mechanism showed that the most favorable activation free energy involves a rotation of the bridging CO to an apical position followed by activation of H2 with the help of the internal amine to give a bridging hydride intermediate. © 2013 American Chemical Society.


Feng L.,University of Illinois at Urbana - Champaign | Feng L.,CAS Dalian Institute of Chemical Physics | Musto C.J.,University of Illinois at Urbana - Champaign | Suslick K.S.,University of Illinois at Urbana - Champaign
Journal of the American Chemical Society | Year: 2010

A colorimetric detection method using amine-functionalized polymer films doped with a pH indicator has been developed for the rapid, sensitive, and quantitative detection of gaseous formaldehyde at concentrations well below the immediately dangerous to life or health (IDLH) limit. In 1 min, visible color changes are easily observed, even down to the permissible exposure limit (PEL) at 750 ppb. The limit of detection is below 50 ppb (7% of the PEL) after 10 min of exposure. This sensor is essentially unaffected by changes in humidity or temperature (4 to 50 °C) and is not sensitive to common interferents. Copyright © 2010 American Chemical Society.


Schwenzer B.,Pacific Northwest National Laboratory | Zhang J.,CAS Dalian Institute of Chemical Physics | Kim S.,Pacific Northwest National Laboratory | Li L.,Pacific Northwest National Laboratory | And 2 more authors.
ChemSusChem | Year: 2011

Large-scale energy storage has become the main bottleneck for increasing the percentage of renewable energy in our electricity grids. Redox flow batteries are considered to be among the best options for electricity storage in the megawatt range and large demonstration systems have already been installed. Although the full technological potential of these systems has not been reached yet, currently the main problem hindering more widespread commercialization is the high cost of redox flow batteries. Nafion, as the preferred membrane material, is responsible for about 11% of the overall cost of a 1 MW/8MWh system. Therefore, in recent years two main membrane-related research threads have emerged: 1) chemical and physical modification of Nafion membranes to optimize their properties with regard to vanadium redox flow battery (VRFB) application; and 2) replacement of the Nafion membranes with different, less expensive materials. This review summarizes the underlying basic scientific issues associated with membrane use in VRFBs and presents an overview of membrane-related research approaches aimed at improving the efficiency of VRFBs and making the technology cost-competitive. Promising research strategies and materials are identified and suggestions are provided on how materials issues could be overcome. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sun J.,Washington State University | Karim A.M.,Pacific Northwest National Laboratory | Mei D.,Pacific Northwest National Laboratory | Engelhard M.,Pacific Northwest National Laboratory | And 3 more authors.
Applied Catalysis B: Environmental | Year: 2015

The reaction pathway of ethanol steam reforming on Co-ZrO2 has been identified and the active sites associated with each step are proposed. Ethanol is converted into acetaldehyde and then into acetone, followed by acetone steam reforming. More than 90% of carbon was found to follow this reaction pathway. N2 sorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), in situ X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, as well as theoretical density functional theory (DFT) calculations have been employed to identify the structure and functionality of the catalysts, which was further used to correlate their performance in ethanol steam reforming (ESR). It was found that metallic cobalt is mainly responsible for the acetone steam-reforming reactions, while CoO and basic sites on the support play a key role in converting ethanol into acetone via dehydrogenation and condensation/ketonization reaction pathways. The current work provides fundamental understanding of the ethanol steam-reforming reaction mechanisms on Co-ZrO2 catalysts and sheds light on the rational design of selective and durable ethanol steam-reforming catalysts. © 2014 Elsevier B.V.


Meng L.,Polytechnic Institute of Porto | Meng L.,University of Minho | Li C.,CAS Dalian Institute of Chemical Physics
Nanoscience and Nanotechnology Letters | Year: 2011

Three different thickness dense TiO2 (150 nm, 300 nm and 450 nm respectively) films were deposited on ITO substrates by dc reactive magnetron sputtering technique. These dense TiO2 films were used as the blocking layers. After that, TiO2 nanorod films were deposited on these dense TiO2 films by same technique. Both the dense and nanorod TiO2 films have an anatase phase. The dense TiO2 films have an orientation along the [101] direction and the TiO2 nanorod films show a very strong orientation along the [110] direction. These TiO 2 materials were sensitized by N719 dye and the DSSCs were assembled using them as photoelectrode. The effect of the blocking layer on the efficiency of the DSSCs is discussed. The DSSC assembled using TiO2 nanorod film with 300 nm thickness blocking layer shows a high efficiency of 2.07%. Copyright © 2011 American Scientific Publishers.


Tian Z.,Pacific Northwest National Laboratory | Tian Z.,CAS Dalian Institute of Chemical Physics | Tolic N.,Pacific Northwest National Laboratory | Zhao R.,Pacific Northwest National Laboratory | And 7 more authors.
Genome Biology | Year: 2012

Post-translational modifications (PTMs) of core histones work synergistically to fine tune chromatin structure and function, generating a so-called histone code that can be interpreted by a variety of chromatin interacting proteins. We report a novel online two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) platform for high-throughput and sensitive characterization of histone PTMs at the intact protein level. The platform enables unambiguous identification of 708 histone isoforms from a single 2D LC-MS/MS analysis of 7.5 μg purified core histones. The throughput and sensitivity of comprehensive histone modification characterization is dramatically improved compared with more traditional platforms. © 2012 Tian et al.; licensee BioMed Central Ltd.


Li G.-Y.,CAS Dalian Institute of Chemical Physics | Li G.-Y.,Hebei United University | Chu T.,CAS Dalian Institute of Chemical Physics | Chu T.,Qingdao University
Physical Chemistry Chemical Physics | Year: 2011

The fluoride-sensing mechanism of the sensor 2-(2′-phenylurea-phenyl) benzoxazole (PUBO) has been investigated by means of the TD-DFT method. The present theoretical study indicates that there is an excited-state intramolecular proton transfer (ESIPT) process in the sensor PUBO. The added fluoride anion could capture the proton in the free N-H moiety instead of the hydrogen-bonding one. The experimental UV/Vis and fluorescence spectra (J. Org. Chem. 2007, 72, 62) are well reproduced by the calculated vertical excitation energies in the ground state and the first singlet excited state. For example, the calculated emission wavelength of PUBO at 534 nm is very close to the fluorescence band at 554 nm. Furthermore, we theoretically confirmed that the added fluoride anions could inhibit the ESIPT process in PUBO. But different from the classical ESIPT-inhibition mechanism, the ESIPT process in the sensor PUBO is inhibited by the high energy barrier of its deprotonated form rather than by the absence of the transferred proton. © the Owner Societies 2011.


Wu H.,U.S. National Institute of Standards and Technology | Wu H.,University of Maryland University College | Chua Y.S.,U.S. National Institute of Standards and Technology | Chua Y.S.,CAS Dalian Institute of Chemical Physics | And 9 more authors.
Journal of the American Chemical Society | Year: 2013

UiO-66 is a highly important prototypical zirconium metal-organic framework (MOF) compound because of its excellent stabilities not typically found in common porous MOFs. In its perfect crystal structure, each Zr metal center is fully coordinated by 12 organic linkers to form a highly connected framework. Using high-resolution neutron power diffraction technique, we found the first direct structural evidence showing that real UiO-66 material contains significant amount of missing-linker defects, an unusual phenomenon for MOFs. The concentration of the missing-linker defects is surprisingly high, ∼10% in our sample, effectively reducing the framework connection from 12 to ∼11. We show that by varying the concentration of the acetic acid modulator and the synthesis time, the linker vacancies can be tuned systematically, leading to dramatically enhanced porosity. We obtained samples with pore volumes ranging from 0.44 to 1.0 cm3/g and Brunauer-Emmett-Teller surface areas ranging from 1000 to 1600 m2/g, the largest values of which are ∼150% and ∼60% higher than the theoretical values of defect-free UiO-66 crystal, respectively. The linker vacancies also have profound effects on the gas adsorption behaviors of UiO-66, in particular CO2. Finally, comparing the gas adsorption of hydroxylated and dehydroxylated UiO-66, we found that the former performs systematically better than the latter (particularly for CO2) suggesting the beneficial effect of the -OH groups. This finding is of great importance because hydroxylated UiO-66 is the practically more relevant, non-air-sensitive form of this MOF. The preferred gas adsorption on the metal center was confirmed by neutron diffraction measurements, and the gas binding strength enhancement by the -OH group was further supported by our first-principles calculations. © 2013 American Chemical Society.


Kim H.N.,Ewha Womans University | Lee E.-H.,Gyeongsang National University | Xu Z.,Ewha Womans University | Xu Z.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Biomaterials | Year: 2012

G-quadruplexes, formed of four stranded guanine bases stabilized by monovalent cations, serve important role in cancer cell growth and control gene expression in telomere. Since there are various types of quadruplex structures, rapid and simple screening methods with high selectivity, sensitivity and nontoxicity are required for understanding about the biological roles of quadruplex DNA as well as in designing therapeutics. Herein, we report a pyrene-imidazolium derivative, JY-1, which can with high selectivity recognize G-quadruplex using fluorescence and NMR spectroscopy. This is the first example based on the imidazolium derivative, which can detect the G-quadruplex directly to utilize the excimer/monomer emission change in pyrene fluorophore. The selectivity of strong binding to a specific sequence can allow for quadruplex sensing and the detection method presented here is very simple, using fluorescence and NMR study. Also, the groove binding characteristic of JY-1 to the G-quadruplex has a relatively low nonspecific toxicity and the structure-specific differences in fluorescent character between DNA duplex and G-quadruplex may offer more discovery and application in biological study. © 2011 Elsevier Ltd.


Cai D.,South China University of Technology | Wang S.,South China University of Technology | Lian P.,Kunming University of Science and Technology | Zhu X.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Electrochimica Acta | Year: 2013

A new facile approach is proposed to synthesize nitrogen-doped graphene sheets with the nitrogen-doping level as high as 7.04 at.% by thermal annealing pristine graphene sheets and low-cost industrial material melamine. The high-level nitrogen-doped graphene sheets exhibit a superhigh initial reversible capacity of 1123 mAh g-1 at a current density of 50 mA g -1. More significantly, even at an extremely high current density of 20 A g-1, highly stable capacity of about 241 mAh g-1 could still be obtained. Such an electrochemical performance is superior to those previously reported nitrogen-doped graphene sheets. The excellent electrochemical performance can be attributed to the two-dimensional structure, disordered surface morphology, high nitrogen-doping level, and the existence of pyridinic nitrogen atoms. The results indicate that the high-level nitrogen-doped graphene sheets could be a promising anode material for high-performance lithium-ion batteries. © 2012 Elsevier Ltd.


Zhang L.,South China University of Technology | Wang S.,South China University of Technology | Cai D.,South China University of Technology | Lian P.,Kunming University of Science and Technology | And 3 more authors.
Electrochimica Acta | Year: 2013

A novel cathode material for lithium-ion batteries, carbon-coated Li 3V2(PO4)3 particles which anchored onto graphene sheets (Li3V2(PO4) 3@C/graphene) have been prepared by a modified Pechini method. It is first proposed that the graphene oxide can act as a chelating agent in the reaction process. The nanocomposite is characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and element analysis. The composite shows excellent C-rate performance, delivered capacities of 104, 91 and 85 mAh g-1 at 5, 30 and 50 C in the voltage range of 3.0-4.3 V, respectively. Moreover, the cycling performance is also improved in higher voltage range of 3.0-4.8 V. The capacity retention is 83% with the capacity of 131 mAh g-1 at 10 C after 100 cycles. The outstanding features are desirable and enable the material to be an excellent cathode for lithium-ion batteries. © 2012 Elsevier Ltd. All rights reserved.


Zhuang W.,CAS Dalian Institute of Chemical Physics | Cui R.Z.,Hong Kong University of Science and Technology | Silva D.-A.,Hong Kong University of Science and Technology | Huang X.,Hong Kong University of Science and Technology
Journal of Physical Chemistry B | Year: 2011

We proposed a computational protocol of simulating the T-jump peptide unfolding experiments and the related transient IR and two-dimensional IR (2DIR) spectra based on the Markov state model (MSM) and nonlinear exciton propagation (NEP) methods. MSMs partition the conformation space into a set of nonoverlapping metastable states, and we can calculate spectra signal for each of these states using the NEP method. Thus the overall spectroscopic observable for a given system is simply the sum of spectra of different metastable states weighted by their populations. We show that results from MSMs constructed from a large number of simulations have a much better agreement with the equilibrium experimental 2DIR spectra compared to that generated from straightforward MD simulations starting from the folded state. This indicates that a sufficient sampling of important relevant conformational states is critical for calculating the accurate spectroscopic observables. MSMs are also capable of simulating the unfolding relaxation dynamics upon the temperature jump. The agreement of the simulation using MSMs and NEP with the experiment not only provides a justification for our protocol, but also provides the physical insight of the underlying spectroscopic observables. The protocol we developed has the potential to be extended to simulate a wide range of fast triggering plus optical detection experiments for biomolecules. © 2011 American Chemical Society.


Yin M.,Shaanxi Normal University | Yin M.,Xi'an Technological University | Liu M.,Shaanxi Normal University | Liu S.,Shaanxi Normal University | Liu S.,CAS Dalian Institute of Chemical Physics
Journal of Alloys and Compounds | Year: 2014

ZnO nanorods with a range of diameter were synthesized by a one-step solvothermal method via adjusting ethanol content in solvents. Material characterization has included XRD, SEM, PL and XPS. It was found that diameter of the ZnO nanorods can be regulated by adjusting ethanol content in solvent. When the ethanol content was increased from 10% to 50%, average diameter of the resultant ZnO nanorods decreased from 360 to 220 nm monotonically. It is also found that ZnO nanorods (a20) prepared with 20% ethanol in solvent has the best crystallinity as revealed in XRD analysis. PL and XPS analyses suggest that the ZnO nanorods are Zn-rich - a beneficial factor to gas sensing response. Gas sensor fabricated using a20 gave the best alcohol vapor response. © 2013 Elsevier B.V. All rights reserved.


Wei J.,Sichuan University | Zhang X.,CAS Dalian Institute of Chemical Physics | Zhao Y.,CAS Dalian Institute of Chemical Physics | Li R.,Sichuan University | Yang Q.,CAS Dalian Institute of Chemical Physics
ChemCatChem | Year: 2014

The polymer-inorganic hybrid core-shell nanospheres with N-(para-toluenesulfonyl)-1,2-diphenylethylenediamine in the core and the poly(methyl acrylate) (PMA) polymer in the shell were prepared by using a sol-gel process. The surface properties of solid catalysts were modified by controlling PMA and the cetyltrimethylammonium bromide surfactant in the shell. The water contact angle results suggest that the presence of PMA and cetyltrimethylammonium bromide in the shell increases the surface hydrophobicity. In the Rh-catalyzed transfer hydrogenation of aromatic ketones in aqueous HCOONa, the solid catalyst with higher surface hydrophobicity demonstrates higher activity, which suggests that suitable surface properties increase the reaction rate by increasing the diffusion rates of hydrophobic substrates. Furthermore, this heterogeneous catalyst can be reused conveniently without loss of ee values. Clever condensation: A sol-gel process is used for the synthesis of polymer-inorganic hybrid core-shell composites with a mixture of poly(methyl acrylate)-organosilane (PMA SiO2) and tetraethoxysilane as a co-condensed silane source and the polystyrene-supported N-(para-toluenesulfonyl)-1,2-diphenylethylenediamine-type ligand as a polymer core. These core-shell materials demonstrate high reactivity and excellent ee values for the asymmetric transfer hydrogenation of aromatic ketones in aqueous HCOONa. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Yin M.,Shaanxi Normal University | Yin M.,Xi'an Technological University | Liu S.,Shaanxi Normal University | Liu S.,CAS Dalian Institute of Chemical Physics
Sensors and Actuators, B: Chemical | Year: 2014

ZnO hollow spherical samples with different surface roughness have been synthesized using a one-step, template-free hydrothermal method. Materials characterization has included XRD, SEM, TEM, XPS and XRF. It was found that the surface roughness of the ZnO hollow spheres can be tuned from rough to smooth via regulating trisodium citrate concentration during the synthesis. When 2 mM of trisodium citrate was used, ZnO hollow spheres showed the roughest surface morphology. With increasing the citrate concentration from 2 to 6 mM, the resultant ZnO hollow sphere morphology became increasingly denser and smoother. When the citrate concentration was further increased to 8 mM, however, the morphology became rough again. Sensors fabricated using the ZnO hollow spheres were characterized by the response to alcohol vapor. The roughest sample gave the best sensor response toward 10-500 ppm alcohol vapor, about 11-16 times higher than the reference one prepared without citrate. This corresponds to a remarkable sensor response as high as 402 and an extrapolated detection limit 0.5 ppm. The reasons behind the improvements in sensor performance are discussed. © 2014 Elsevier B.V.


Wei J.,Sichuan University | Zhang X.,CAS Dalian Institute of Chemical Physics | Zhao Y.,CAS Dalian Institute of Chemical Physics | Li R.,Sichuan University
Macromolecular Chemistry and Physics | Year: 2013

Novel (R)-(+)-1,1′-bi-2-naphthol ((R)-(+)-BINOL)-based conjugated microporous polymers (CMP1-4) with high Brunauer-Emmett-Teller (BET) surface area are synthesized through Sonogashira-Hagihara cross-coupling of di-/tetra-bromo-substituted (R)-(+)-BINOL derivatives and 1,3,5- triethynylbenzene. Fluorescence studies find that CMP4 can act as a sensitive and enantioselective sensor for chiral amino alcohols, such as 2-amino-1-propanol (AA1), 2-amino-3-methyl-1-butanol (AA2), and 2-amino-2-phenylethanol (AA3), which expands the application scope of conjugated microporous polymers. Novel (R)-(+)-1,1′-bi-2-naphthol ((R)-(+)-BINOL)-based conjugated microporous polymers are synthesized and applied for fluorescence sensing of amino alcohols. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zeng Z.,Monash University | Zeng Z.,CAS Dalian Institute of Chemical Physics | Li J.,CAS Dalian Institute of Chemical Physics | Hugel H.M.,RMIT University | And 2 more authors.
TrAC - Trends in Analytical Chemistry | Year: 2014

The power of comprehensive two-dimensional gas chromatography (GC × GC) for the study of complex mixtures has been indisputably proved in the past several decades. This review encompasses the whole of GC × GC-related data processing and summarizes relevant applications. We include theoretical introduction to some specific methods and studies to aid readers' understanding of chemometrics strategies for advanced data interpretation. © 2013 Elsevier Ltd.


Zhang G.,Dalian University of Technology | Wang S.,Dalian University of Technology | Zhao S.,Dalian University of Technology | Fu L.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2011

Heterogeneous electrocatalytic wet H2O2 oxidation technique for the removal of azo dye amaranth from aqueous solution was studied in the presence of solid CuO/γ-Al2O3 catalyst and anthraquinonemonosulphonate/polypyrrole (AQS/PPy) composite cathode able to electrogenerate H2O2 in situ. The spherical CuO/γ-Al2O3 catalysts with various CuO loadings and calcined at different temperatures were characterized by BET, ESEM-EDS, XRD and XPS. Several parameters affecting H2O2 electrogeneration and dye degradation such as solution pH, cathode potential (Eca), oxygen flow rate (VO2), CuO loading, reaction temperature as well as catalyst calcination temperature were investigated. Experimental results revealed that the optimal condition for H2O2 electrogeneration on the AQS/PPy composite modified cathode is VO2=0.4 ml min-1, Eca=-0.4V and pH 4.3. On this occasion, ca. 90% chroma decay and 60% TOC removal of dye were achieved with 450°C-calcined 5.78wt%-CuO/γ-Al2O3 catalyst and 70°C reaction temperature. Dye degradation follows the second-order kinetics. Leaching tests showed that the leaching copper amount during the oxidation is only 4.0-7.0% per run and the role of heterogeneous activity is dominant. The catalytic activity of CuO/γ-Al2O3 catalyst could be recovered after multiple runs by a re-calcination step. Furthermore, the stability of the AQS/PPy composite after consecutive operation was also investigated by chronoamperometric and EIS techniques. © 2011 Elsevier B.V.


Jiang L.,CAS Dalian Institute of Chemical Physics | Zhang M.,CAS Dalian Institute of Chemical Physics | Li J.,Hong Kong University of Science and Technology | Wen W.,Hong Kong University of Science and Technology | Qin J.,CAS Dalian Institute of Chemical Physics
Advanced Materials | Year: 2012

A simple, new approach to localizing electrospun nanofiber scaffolds simply by direct writing of SU-8 photoresist followed by UV polymerization is presented. This method allows 3D cell culture arrays to be produced (see figure) and it can be integrated with microfluidic devices easily to enable low-cost high-throughput cellular assays within an addressable 3D environment, which is attractive for use in drug screening, stem cell research, tissue engineering, and regenerative medicine. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xu S.,CAS Yantai Institute of Coastal Zone Research | Xu S.,University of Chinese Academy of Sciences | Chen L.,CAS Yantai Institute of Coastal Zone Research | Li J.,CAS Yantai Institute of Coastal Zone Research | And 2 more authors.
Journal of Hazardous Materials | Year: 2012

A novel functional monomer T-IPTS, 3-isocyanatopropyltriethoxysilane (IPTS) bearing thymine (T) bases, was synthesized for imprinting Hg 2+. Then a novel Hg 2+ ionic imprinted polymers (IIPs) based on thymine-Hg 2+-thymine (T-Hg 2+-T) interactions, i.e. Hg-IIPs-T, were prepared by sol-gel process for the first time in this work. The Hg-IIPs-T exhibited excellent selectivity towards Hg 2+ over Cd 2+, Zn 2+ Pb 2+, Co 2+, Mn 2+, Mg 2+ and Ca 2+, due to the specific T-Hg 2+-T interactions with high selectivity and high affinity. Accordingly, Hg-IIPs-T were used as solid-phase extraction (SPE) sorbents for preconcentration of trace Hg 2+ in water samples, and satisfactory recoveries ranging from 95.2 to 116.3% were obtained. Also, under optimized conditions, preconcentration factor and detection limit were achieved of 200 and 0.03μgL -1, respectively. The IIPs-T-SPE proved to be a rapid and high-effective cleanup and enrichment method for trace Hg 2+ in water samples. More importantly, these results indicated that devising and synthesizing new functional monomers tailor-made for template would become a general promising way to improve the selectivity and stability of IIPs. © 2012 Elsevier B.V.


Li X.,CAS Dalian Institute of Chemical Physics | Li X.,University of South China | Gong X.,CAS Dalian Institute of Chemical Physics | Zhao M.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Organic Letters | Year: 2011

Rhodium(III)-catalyzed oxidative olefination of N-(1-naphthyl)sulfonamides has been achieved at the peri position. Three categories of olefins have been successfully applied. Activated olefins reacted to afford five-membered azacycles as a result of oxidative olefination-hydroamination. Unactivated olefins reacted to give the olefination product. 2-fold oxidative C-C and C-N coupling was achieved for allylbenzenes. © 2011 American Chemical Society.


Lahankar S.A.,Montana State University | Zhang J.,Montana State University | Minton T.K.,Montana State University | Minton T.K.,CAS Dalian Institute of Chemical Physics | McKendrick K.G.,Heriot - Watt University
Journal of the American Chemical Society | Year: 2014

The first quantum-state-resolved distributions over the full range of available product levels are reported for any isotopic variant of the elementary reaction of O(3P) with molecular hydrogen. A laser-detonation source was used to produce a hyperthermal oxygen-atom beam, which allowed for sufficient collision energy to surmount the reaction barrier. This beam was crossed by a supersonic beam of D2. The nascent OD products were detected by laser-induced fluorescence. OD rotational distributions in vibrational states v′ = 0, 1, and 2 at a collision energy of 25 kcal mol-1 are reported, together with distributions for the dominant product vibrational level, v′= 0, at lower collision energies of 20 and 15 kcal mol-1. The OD product is highly rotationally excited, to a degree that declines as expected for the higher vibrational levels or for reductions in the collision energy. The measured rovibrational distributions at the highest collision energy are in excellent agreement with previous theoretical predictions based on quantum scattering calculations on the triplet potential energy surfaces developed by Rogers et al. (J. Phys. Chem. A 2000, 104, 2308-2325). However, no significant OD spin-orbit preference was observed, in contrast to the predictions of most existing theoretical models of the non-adiabatic dynamics based on the widely used reduced-dimensional four-state model of Hoffmann and Schatz (J. Chem. Phys. 2000, 113, 9456-9465). Furthermore, a clear observed preference for OD π(A′) Λ-doublet levels is not consistent with a simple extrapolation of the calculated relative reaction cross sections on intermediate surfaces of 3A′ and 3A symmetry. © 2014 American Chemical Society.


Yin M.,Shaanxi Normal University | Yin M.,Xi'an Technological University | Liu M.,Shaanxi Normal University | Liu S.,Shaanxi Normal University | Liu S.,CAS Dalian Institute of Chemical Physics
Sensors and Actuators, B: Chemical | Year: 2013

An one-step solvothermal synthesis technique has been developed to prepare uniform ZnO nanorods for gas sensor applications. Material characterization has included X-ray diffraction (XRD), scanning electron microcopy (SEM) and photoluminescence (PL). It has been found that ZnO nanorods prepared with ethanol solvent not only exhibit cleaner and smoother surfaces, larger crystallite size, reduced strain, smaller diameter and more donor-related surface defects, but also gave better gas sensing performance comparing to the ZnO nanorods prepared with pure water solvent. It was found that at alcohol level of 500 ppm, such sensor showed the response of 142, among the highest reported values achieved for ZnO nanorod sensors. © 2013 Elsevier B.V. All rights reserved.


Wang X.,CAS Dalian Institute of Chemical Physics | Wang X.,University of Chinese Academy of Sciences | Lu X.,CAS Dalian Institute of Chemical Physics | Wu L.,Chinese Academy of Fishery Sciences | Chen J.,CAS Dalian Institute of Chemical Physics
Biosensors and Bioelectronics | Year: 2015

As is well known, bisphenol A (BPA), usually exists in daily plastic products, is one of the most important endocrine disrupting chemicals. In this work, copper-centered metal-organic framework (Cu-MOF) was synthesized, which was characterized by SEM, TEM, XRD, FTIR and electrochemical method. The resultant Cu-MOF was explored as a robust electrochemical biosensing platform by choosing tyrosinase (Tyr) as a model enzyme for ultrasensitive and rapid detection of BPA. The Cu-MOF provided a 3D structure with a large specific surface area, which was beneficial for enzyme and BPA absorption, and thus improved the sensitivity of the biosensor. Furthermore, Cu-MOF as a novel sorbent could increase the available BPA concentration to react with tyrosinase through π-π stacking interactions between BPA and Cu-MOF. The Tyr biosensor exhibited a high sensitivity of 0.2242A M-1 for BPA, a wide linear range from 5.0×10-8 to 3.0×10-6moll-1, and a low detection limit of 13nmoll-1. The response time for detection of BPA is less than 11s. The proposed method was successfully applied to rapid and selective detection of BPA in plastic products with satisfactory results. The recoveries are in the range of 94.0-101.6% for practical applications. With those remarkable advantages, MOFs-based 3D structures show great prospect as robust biosensing platform for ultrasensitive and rapid detection of BPA. © 2014 Published byElsevier B.V.


Yu Y.,CAS Dalian Institute of Chemical Physics | Wen H.,CAS Dalian Institute of Chemical Physics | Ma J.,CAS Dalian Institute of Chemical Physics | Lykkemark S.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Advanced Materials | Year: 2014

Biomimetic and flexible bamboo-like hybrid fibers are produced using a novel one-step strategy. By combining a droplet microfluidic technique with a wet-spinning process, biocompatible microfibers are incorporated with polymer spheres or multicellular spheroids. As a result of the controllability of this approach, it has potential applications in materials science and tissue engineering. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li X.,CAS Dalian Institute of Chemical Physics | Pan X.,CAS Dalian Institute of Chemical Physics | Yu L.,CAS Dalian Institute of Chemical Physics | Ren P.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Nature Communications | Year: 2014

Acetylene hydrochlorination is an important coal-based technology for the industrial production of vinyl chloride, however it is plagued by the toxicity of the mercury chloride catalyst. Therefore extensive efforts have been made to explore alternative catalysts with various metals. Here we report that a nanocomposite of nitrogen-doped carbon derived from silicon carbide activates acetylene directly for hydrochlorination in the absence of additional metal species. The catalyst delivers stable performance during a 150 hour test with acetylene conversion reaching 80% and vinyl chloride selectivity over 98% at 200 °C. Experimental studies and theoretical simulations reveal that the carbon atoms bonded with pyrrolic nitrogen atoms are the active sites. This proof-of-concept study demonstrates that such a nanocomposite is a potential substitute for mercury while further work is still necessary to bring this to the industrial stage. Furthermore, the finding also provides guidance for design of carbon-based catalysts for activation of other alkynes. © 2014 Macmillan Publishers Limited.


Yang X.,Beihang University | Guo F.,Beihang University | Xue S.,CAS Dalian Institute of Chemical Physics | Wang X.,Beihang University
Renewable and Sustainable Energy Reviews | Year: 2016

Algae are considered to be the most viable feedstock for alternative aviation fuel production. The alternative (nonpetroleum) fuel from biomass could be produced as "drop-in" fuels with no effects on flight safety and would be interchangeable with current fuels in performance and handling. Accordingly, alternative fuels blended with petroleum fuels should meet jet fuel's. © 2015 Elsevier Ltd. All rights reserved.


Ma J.,CAS Dalian Institute of Chemical Physics | Hui Y.S.,Hong Kong University of Science and Technology | Zhang M.,CAS Dalian Institute of Chemical Physics | Yu Y.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Small | Year: 2013

A microfluidic approach to a honeycomb-structure material based on the synergistic effects of polymer rapid precipitation, double emulsion templating, and internal effervescent salt decomposition is reported. The delicate honeycomb structure exhibits unique characteristics with an external nanopore membrane and internal multiple cavities. The biological functionality of the artificial structure is explored to serve as microcarriers for cell culture and drug release, indicating their attractive properties for potential biomedical applications. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wu X.,CAS Institute of Botany | Wu X.,Wenzhou Medical College | Wu X.,CAS Dalian Institute of Chemical Physics | Song Y.,Wenzhou Medical College
BMC Genomics | Year: 2011

Background: microRNAs (miRNAs) represent a class of small (typically 22 nucleotides in length) non-coding RNAs that can degrade their target mRNAs or block their translation. Recent disease research showed the exposure to some environmental chemicals (ECs) can regulate the expression patterns of miRNAs, which raises the intriguing question of how miRNAs and their targets cope with the exposure to ECs throughout the genome.Results: In this study, we comprehensively analyzed the properties of genes regulated by ECs (EC-genes) and found miRNA targets were significantly enriched among the EC-genes. Compared with the non-miRNA-targets, miRNA targets were roughly twice as likely to be EC-genes. By investigating the collection methods and other properties of the EC-genes, we demonstrated that the enrichment of miRNA targets was not attributed to either the potential collection bias of EC-genes, the presence of paralogs, longer 3'UTRs or more conserved 3'UTRs. Finally, we identified 1,842 significant concurrent interactions between 407 miRNAs and 497 ECs. This association network of miRNAs-ECs was highly modular and could be separated into 14 interconnected modules. In each module, miRNAs and ECs were closely connected, providing a good method to design accurate miRNA markers for ECs in toxicology research.Conclusions: Our analyses indicated that miRNAs and their targets played important roles in cellular responses to ECs. Association analyses of miRNAs and ECs will help to broaden the understanding of the pathogenesis of such chemical components. © 2011 Wu and Song; licensee BioMed Central Ltd.


Chen J.,Nanjing Southeast University | Lei W.,Nanjing Southeast University | Deng W.Q.,CAS Dalian Institute of Chemical Physics
Nanoscale | Year: 2011

An efficient photoelectrode is fabricated by sequentially assembling 2.5 nm and 3.5 nm CdSe quantum dots (QDs) onto a TiO2 film. As revealed by UV-vis absorption spectroscopy, two sizes of CdSe QD can be effectively adsorbed on the TiO2 film. With a broader light absorption range and better coverage of CdSe QDs on the TiO2 film, a power conversion efficiency of 1.26% has been achieved for the TiO2/CdSe QD (2.5 nm)/CdSe QD (3.5 nm) cell under the illumination of one Sun (AM 1.5G, 100 mW cm-2). Electrochemical impedance spectroscopy shows that the electron lifetime for the device based on TiO2/CdSe QD (2.5 nm)/CdSe QD (3.5 nm) is longer than that for devices based on TiO2/CdSe QD (2.5 nm) and TiO 2/CdSe QD (3.5 nm), indicating that the charge recombination at the interface is reduced by sensitizing with two kinds of CdSe QDs. © 2011 The Royal Society of Chemistry.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ENERGY.2009.5.1.1 | Award Amount: 5.24M | Year: 2010

Hydrogen membrane reactors are an attractive technology for pre-combustion carbon dioxide capture in both coal and gas fired power stations because they combine the efficient conversion of syngas into hydrogen fuel with capture of the remaining carbon dioxide in one reactor. The carbon dioxide is produced at high pressure, reducing the compression energy for transport and storage. CACHET II project will develop innovative metallic membranes and modules for high capacity hydrogen production and separation from a number of fuel sources including natural gas and coal. The DICP membrane developed in FP6 project CACHET along with novel seal and substrate technology will be scaled up and undergo long term stability testing. An optimisation design tool will be built to include the relationship of all key operating parameters; this tool will be used to specify an optimised pilot and commercial membrane module design. The project will research novel binary and tertiary palladium alloys for improved durability and permeance for application to solid based fuels derived syngas and high temperature integrated reforming processes. Fundamental research on high temperature sulphur removal systems will enable sulphur tolerant membranes to become an economic possibility.


Xie H.,CAS Dalian Institute of Chemical Physics | Xie H.,Dalian National Laboratory for Clean Energy | Zhao Z.K.,CAS Dalian Institute of Chemical Physics | Zhao Z.K.,Dalian National Laboratory for Clean Energy | Wang Q.,CAS Dalian Institute of Chemical Physics
ChemSusChem | Year: 2012

In this work, we found that lignosulfonic acid (LS), which is a waste byproduct from the paper industry, in ionic liquids (ILs) can catalyze the dehydration of fructose and inulin into 5-hydroxymethylfurfural (HMF) efficiently, which is a promising potential substitute for petroleum-based building blocks. The effects of reaction time, temperature, catalyst loading, and reusability of the catalytic system were studied. It was found that a 94.3% yield of HMF could be achieved in only 10 min at 100°C under mild conditions. The reusability study of the LS-IL catalytic system after removal of HMF by ethyl acetate extraction demonstrated that the catalytic activity decreased from 77.4 to 62.9% after five cycles and the catalytic activity could be recovered after simply removing the accumulated humins by filtration after adding ethanol to the LS-ILs. The integrated utilization of a biorenewable feedstock, catalyst, and ILs is an example of an ideal green chemical process. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chen C.-M.,Shanxi Institute of Coal CAS Chemistry | Zhang Q.,Tsinghua University | Huang C.-H.,National Tsing Hua University | Zhao X.-C.,CAS Dalian Institute of Chemical Physics | And 6 more authors.
Chemical Communications | Year: 2012

A three-dimensional bubble graphene film, with controllable and uniform macropores and tailorable microstructure, was fabricated by a facile hard templating strategy and exhibit extraordinary electrochemical capacitance with high rate capability (1.0 V s -1). © 2012 The Royal Society of Chemistry.


Liu X.,CAS Dalian Institute of Chemical Physics | Liu X.,National Taiwan University | Wang A.,CAS Dalian Institute of Chemical Physics | Zhang T.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Catalysis Today | Year: 2011

Au-Cu bimetallic catalysts with Au/Cu ratios ranging from 3/1 to 20/1 were prepared on silica gel support by a two-step method. The catalysts were characterized by ICP, XRD and TEM. The results showed that, irrespective of Au/Cu ratios, all the bimetallic nanoparticles had significantly reduced particle sizes (3.0-3.6 nm) in comparison with monometallic gold catalysts (5.7 nm). Both CO oxidation and PROX reactions were employed to evaluate the catalytic activities of Au-Cu bimetallic catalysts. For CO oxidation, the alloy catalysts show non-monotonic temperature dependence showing a valley in the intermediate temperature range. The catalyst with Au/Cu ratio of 20/1 gave the highest activity at room temperature, but its activity showed the deepest valley with increasing the reaction temperature. On the other hand, the catalyst with Au/Cu ratio of 3/1 exhibited the best performance for PROX reaction. For the Au/Cu ratios investigated, the bimetallic catalysts showed superior performance to monometallic gold catalysts, demonstrating the synergy between gold and copper. © 2010 Elsevier B.V. All rights reserved.


Zeng Z.-H.,CAS Dalian Institute of Chemical Physics | Zeng Z.-H.,University of Chinese Academy of Sciences | Da Silva J.L.F.,University of Sao Paulo | Li W.-X.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2010

In this work, we report a density functional theory study of nitric oxide (NO) adsorption on close-packed transition metal (TM) Rh(111), Ir(111), Pd(111) and Pt(111) surfaces in terms of adsorption sites, binding mechanism and charge transfer at a coverage of ΘNO = 0.25, 0.50, 0.75 monolayer (ML). Based on our study, an unified picture for the interaction between NO and TM(111) and site preference is established, and valuable insights are obtained. At low coverage (0.25 ML), we find that the interaction of NO/TM(111) is determined by an electron donation and back-donation process via the interplay between NO 5σ/2π* and TM d-bands. The extent of the donation and back-donation depends critically on the coordination number (adsorption sites) and TM d-band filling, and plays an essential role for NO adsorption on TM surfaces. DFT calculations shows that for TMs with high d-band filling such as Pd and Pt, hollow-site NO is energetically the most favorable, and top-site NO prefers to tilt away from the normal direction. While for TMs with low d-band filling (Rh and Ir), top-site NO perpendicular to the surfaces is energetically most favorable. Electronic structure analysis show that irrespective of the TM and adsorption site, there is a net charge transfer from the substrate to the adsorbate due to overwhelming back-donation from the TM substrate to the adsorbed NO molecules. The adsorption-induced change of the work function with respect to bare surfaces and dipole moment is however site dependent, and the work function increases for hollow-site NO, but decreases for top-site NO, because of differences in the charge redistribution. The interplay between the energetics, lateral interaction and charge transfer, which is element dependent, rationalizes the structural evolution of NO adsorption on TM(111) surfaces in the submonolayer regime. © 2010 the Owner Societies.


Zhu Y.,Anshan Normal University | Zhang B.,CAS Shenyang Institute of Metal Research | Liu X.,CAS Dalian Institute of Chemical Physics | Wang D.-W.,University of New South Wales | Su D.S.,CAS Shenyang Institute of Metal Research
Angewandte Chemie - International Edition | Year: 2014

Non-precious Fe/N co-modified carbon electrocatalysts have attracted great attention due to their high activity and stability in oxygen reduction reaction (ORR). Compared to iron-free N-doped carbon electrocatalysts, Fe/N-modified electrocatalysts show four-electron selectivity with better activity in acid electrolytes. This is believed relevant to the unique Fe-N complexes, however, the Fe-N structure remains unknown. We used o,m,p-phenylenediamine as nitrogen precursors to tailor the Fe-N structures in heterogeneous electrocatalysts which contain FeS and Fe3C phases. The electrocatalysts have been operated for 5000 cycles with a small 39 mV shift in half-wave potential. By combining advanced electron microscopy and Mössbauer spectroscopy, we have identified the electrocatalytically active Fe-N6 complexes (FeN6, [FeIII(porphyrin)(pyridine)2]). We expect the understanding of the FeN6 structure will pave the way towards new advanced Fe-N based electrocatalysts. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu Y.-H.,Bohai University | Liu Y.-H.,CAS Dalian Institute of Chemical Physics | Lan S.-C.,Bohai University | Li C.-R.,Bohai University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

In this work, the dynamics of hydrogen bonds (as well as the hydrogen-bonded wire) in excited-state tautomerization of 7- hydroxyquinoline·(NH3)3 (7HQ· (NH 3)3) cluster has been investigated by using timedependent density functional theory (TDDFT). It shows that upon an excitation, the hydrogen bond between -OH group in 7-hydroxyquinoline (7HQ) and NH3 moiety would extremely strengthened in S1 state, which could effectively facilitate the releasing of the proton from the phenolic group of 7HQ moiety to the hydrogen-bonded wire and the forming an Eigen-like cationic wire (NH 3 · · · NH4+ ···NH3) in the cluster. To fulfill the different optimal angles of NH4+ in the wire, a wagging motion of hydrogen-bonded wire would occur in excited state. Moreover, the wagging motion of the hydrogen-bonded wire would effectively promote excited-state proton transfer reaction. As the results, an excited-state multiple proton transfer (ESMPT) mechanism containing two concerted and asymmetrical processes has been proposed for the proton transfer dynamics of 7HQ·(NH3) 3 cluster. © 2013 Elsevier B.V. All rights reserved.


Wang A.,CAS Dalian Institute of Chemical Physics | Liu X.Y.,CAS Dalian Institute of Chemical Physics | Mou C.-Y.,National Taiwan University | Zhang T.,CAS Dalian Institute of Chemical Physics
Journal of Catalysis | Year: 2013

In with the course of the "gold rush" in catalysis, gold bimetallic nanocatalysts have attracted considerable interest in the past decade, attributed to their improved sintering resistance, enhanced activity, and more tunable selectivity. In this article, we classify the gold bimetallic catalysts into Au-BM and Au-PGM, based on the chemical properties of the second metal, where BM refers to base metals (Ag, Cu, Ni, Co, etc.) that are characterized by their pronounced effect in promoting oxygen activation in gold-catalyzed oxidation reactions, while PGM refers to platinum group metals (Pt, Pd, Rh, etc.) that are characterized by their remarkable effect in promoting H2 dissociation in gold-catalyzed hydrogenation reactions. The preparation of catalysts with controlled size and composition, their structural evolution under different atmospheres, and the promotional role of the second metal in gold catalysis have been addressed. © 2013 Elsevier Inc. All rights reserved.


Wu S.,CAS Shenyang Institute of Metal Research | Wu S.,University of Chinese Academy of Sciences | Wen G.,CAS Shenyang Institute of Metal Research | Liu X.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
ChemCatChem | Year: 2014

The role of different oxygen functional groups on a carbon catalyst was studied in the reduction of nitrobenzene by using a series of model molecules. The carbonyl and hydroxyl groups played important roles, which may be ascribed to their ability to activate hydrazine. In comparison, the ester, ether, and lactone groups seemed to be inactive, whereas the carboxylic group had a negative effect. The reaction occurred most likely through a direct route, during which nitrosobenzene may be converted directly into aniline. Modeling carbon: Thanks to model molecules, the carbon-catalyzed reduction of nitrobenzene is mimicked. The role of different oxygen functional groups on a carbon catalyst is studied, and the carbonyl and hydroxyl groups seem to be the most important moieties, which may be ascribed to their ability to activate hydrazine. The reaction occurs more likely through a direct route, during which nitrosobenzene may also be converted directly into aniline. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sun Q.,Jilin University | Wang N.,Jilin University | Xi D.,Jilin University | Yang M.,CAS Dalian Institute of Chemical Physics | Yu J.,Jilin University
Chemical Communications | Year: 2014

Using an organosilane surfactant as the mesopore director, hierarchical porous silicoaluminophosphate SAPO-34 is obtained as an assembly of nanocrystallites intergrown into cubic micrometer-sized crystals, which show excellent performance in MTO reactions with a remarkably prolonged catalyst lifetime and enhanced selectivity of ethylene and propylene compared to the conventional microporous SAPO-34. This journal is © the Partner Organisations 2014.


You D.,CAS Dalian Institute of Chemical Physics | Zhang H.,CAS Dalian Institute of Chemical Physics | Sun C.,Dalian RONGKEPOWER Co. | Ma X.,CAS Dalian Institute of Chemical Physics
Journal of Power Sources | Year: 2011

A simple mathematical model is established to predict the self-discharge process in a kilowatt-class vanadium redox flow battery stack. The model uses basic mass transport theory to simulate the transfer of vanadium ions in the battery. The simulation results agree reasonably with the experimental values, confirming the validity of the model. It is found that the diffusion rate of vanadium ions depends on the diffusion coefficient, the partition coefficient and the concentration gradient of the vanadium ions between the two half cells. For the self-discharge process at the initial SOC of 0, the net transfer direction of vanadium ions is towards the negative electrolyte until the diffusion flux of V3+ becomes larger than that of VO2+. For the self-discharge process at the initial SOC of 65%, the net transfer direction of vanadium ions is towards the positive electrolyte at the initial 20 h and then turns to the negative electrolyte. There are two obvious changes in the diffusion flux of vanadium ions at about 33 h and 43 h, corresponding to the vanishing time of VO2+ and V2+ respectively. © 2010 Elsevier B.V. All rights reserved.


Zhang Z.,South-Central University for Nationalities | Liu B.,South-Central University for Nationalities | Zhao Z.,CAS Dalian Institute of Chemical Physics | Zhao Z.,Dalian National Laboratory for Clean Energy
Carbohydrate Polymers | Year: 2012

Conversion of fructose into 5-hydroxymethylfurfural (HMF) catalyzed by Germanium(IV) chloride was studied in Dimethyl sulfoxide (DMSO) and [Bmim]Cl system at room temperature. The structure of ionic liquids and the ratio of ionic liquids to DMSO had a remarkable effect on this new catalytic system. The results indicated that 1-n-butyl-3-methylimidazolium chloride ([Bmim]Cl) was favorable for the dehydration of fructose to HMF. Under optimal conditions, a high HMF yield in 70% was obtained at 25°C. In addition, it was also proved that there was a synergistic effect between the cation and anion of [Bmim]Cl on the dehydration of fructose to HMF by designed experiments. Finally, a possible mechanism for the dehydration of fructose to HMF was proposed. © 2012 Elsevier Ltd. All rights reserved.


Yang G.,CAS Dalian Institute of Chemical Physics | Yang G.,Jilin University | Wei Y.,CAS Dalian Institute of Chemical Physics | Xu S.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
Journal of Physical Chemistry C | Year: 2013

In this work, we systematically investigated the size effect of silicoaluminophosphate molecular sieve catalysts SAPO-34 on the catalytic performance of methanol-to-olefin (MTO) reactions. Four highly crystalline SAPO-34 molecular sieves with different crystallite sizes were synthesized under hydrothermal conditions carried out in conventional or microwave ovens with the same starting gel composition using TEAOH as the structure-directing agent. The as-prepared SAPO-34s have similar composition, and their average crystal size can be controlled between 20 nm and 8 μm. Textural properties and chemical environments of framework atoms as well as acid concentration were characterized by N2 adsorption and NMR measurements. The MTO reactions were carried out over these four SAPO-34 catalysts to study their catalytic performances dependent on the crystal size. The occurrence of catalyst deactivation varied considerably with the crystal size of SAPO-34s. Significantly, the nanosized catalysts, especially the sheetlike SAPO-34 catalyst with 20 nm thickness, exhibited the longest catalyst lifetime and lowest coking rate in MTO reactions. On the basis of the measurement of coke formation and the determination of retained coke species, a scheme is proposed to elucidate the reduction in coke deposition and consequently the remarkably enhanced lifetime on the nanosized SAPO-34 catalysts in methanol conversion. © 2013 American Chemical Society.


Zhang Z.,CAS Dalian Institute of Chemical Physics | Zhang Z.,University of Chinese Academy of Sciences | Zhao Z.K.,CAS Dalian Institute of Chemical Physics | Zhao Z.K.,Dalian National Laboratory for Clean Energy
Bioresource Technology | Year: 2010

Production of 5-hydroxymethylfurfural (HMF) and furfural from lignocellulosic biomass was studied in ionic liquid in the presence of CrCl3 under microwave irradiation. Corn stalk, rice straw and pine wood treated under typical reaction conditions produced HMF and furfural in yields of 45-52% and 23-31%, respectively, within 3 min. This method should be valuable to facilitate energy-efficient and cost-effective conversion of biomass into biofuels and platform chemicals. © 2009 Elsevier Ltd. All rights reserved.


Zhao Z.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Zhao Z.,University of Chinese Academy of Sciences | Tan H.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Zhao H.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | And 4 more authors.
Chemical Communications | Year: 2014

Stable reduced TiO2 rutile nanorods with well-defined facets were prepared by a solvothermal route in the presence of Zn powder. The oxygen vacancy in the TiO2 nanorods, which can be tuned by the amount of Zn, results in a narrow band gap and visible-light photocatalytic activity. © 2014 The Royal Society of Chemistry.


Mou X.,CAS Dalian Institute of Chemical Physics | Zhang B.,CAS Shenyang Institute of Metal Research | Li Y.,CAS Dalian Institute of Chemical Physics | Yao L.,Fritz Haber Institute of the Max Planck Society | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2012

Nanorust: Fe 2O 3 nanomaterials with controllable crystal phase and morphology have been successfully fabricated. The γ-Fe 2O 3 nanorods that are enclosed by the reactive {110} and {100} facets are highly active and distinctively stable for selective catalytic reduction of NO with NH 3. The picture shows the shape and surfaces and the surface atomic configurations of the preferentially exposed {110} and {001} planes. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Shi L.,CAS Dalian Institute of Chemical Physics | Shi L.,University of Chinese Academy of Sciences | Wang A.,CAS Dalian Institute of Chemical Physics | Zhang T.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Journal of Physical Chemistry C | Year: 2013

Au-Pd bimetallic nanocrystals with well-defined dendritic morphology, uniform size, and homogeneous alloy structure were synthesized in an aqueous solution by using ascorbic acid as the reductant and triblock copolymer P123 as the stabilizing agent. In this synthesis, ascorbic acid played a key role in directing the nanodendritic morphology while the presence of Pd was mandatory for the formation of well-defined nanodendrites. Without Pd, only faceted nanoparticles of gold were formed under the same reaction conditions. Other reaction variables such as the addition sequence and the dropping rate of the metal precursors, the type and concentration of the stabilizing agents, and the reaction time and temperature were all found to affect the size uniformity and morphology perfectness to some extent. The Au/Pd atomic ratio could be tuned in a wide range without deteriorating the nanodendritic morphology. The as-prepared Au-Pd nanodendrites exhibited excellent catalytic activities toward electroxidation of methanol and reduction of 2-nitrophenol, and the catalytic performances could be effectively tuned by the Au/Pd ratio. © 2013 American Chemical Society.


Wang C.,CAS Dalian Institute of Chemical Physics | Jia G.,CAS Dalian Institute of Chemical Physics | Li Y.,CAS Dalian Institute of Chemical Physics | Zhang S.,Dalian National Laboratory for Clean Energy | And 2 more authors.
Chemical Communications | Year: 2013

Here we found that the enantioselectivity of G-quadruplex DNA-based Diels-Alder reaction can be switched by just changing Na+ to K +, which is ascribed to the structural transformation of the G-quadruplex from antiparallel to hybrid-type. By tuning the ratio of Na +/K+, the enantioselectivity of the Diels-Alder reaction could be switchable and shows much more sensitive to K+ than to Na+. © 2013 The Royal Society of Chemistry.


Hou C.-J.,CAS Dalian Institute of Chemical Physics | Hou C.-J.,Dalian Polytechnic University | Wang Y.-H.,CAS Dalian Institute of Chemical Physics | Zheng Z.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Organic Letters | Year: 2012

A mild and general iridium-catalyzed, highly enantioselective hydrogenation of sterically hindered N-arylimines with a new H 8-BINOL-derived phosphine-phosphoramidite ligand has been developed. The present catalytic system features high turnover numbers (up to 100000) and good to perfect enantioselectivities (up to 99% ee) for the hydrogenation of a variety of sterically hindered N-arylimines. © 2012 American Chemical Society.


Zhang Z.,CAS Dalian Institute of Chemical Physics | Zhang Z.,University of Chinese Academy of Sciences | Zhao Z.,CAS Dalian Institute of Chemical Physics | Zhao Z.,Dalian National Laboratory for Clean Energy
Bioresource Technology | Year: 2011

Production of 5-hydroxymethylfurfural (HMF) from glucose was studied in ionic liquids in the presence of hydroxyapatite supported chromium chloride (Cr-HAP) using oil-bath heating and microwave irradiation (MI). Compared with oil-bath heating, the MI way obviously increased HMF yield and reduced the reaction time from days to several minutes. A maximum HMF yield of 40% was obtained from the dehydration of glucose under MI in 2.5. min. This method is potential as an energy-efficient and cost-effective approach for the conversion of biomass into platform chemicals. © 2010 Elsevier Ltd.


Zhu Y.,CAS Shenyang Institute of Metal Research | Zhu Y.,Anshan Normal University | Zhang B.,CAS Shenyang Institute of Metal Research | Liu X.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2015

Non-precious Fe/N co-modified carbon electrocatalysts have attracted great attention due to their high activity and stability in oxygen reduction reaction (ORR). Compared to iron-free N-doped carbon electrocatalysts, Fe/N-modified electrocatalysts show four-electron selectivity with better activity in acid electrolytes. This is believed relevant to the unique Fe-N complexes, however, the Fe-N structure remains unknown. We used o,m,p-phenylenediamine as nitrogen precursors to tailor the Fe-N structures in heterogeneous electrocatalysts which contain FeS and Fe3C phases. The electrocatalysts have been operated for 5000 cycles with a small 39 mV shift in half-wave potential. By combining advanced electron microscopy and Mössbauer spectroscopy, we have identified the electrocatalytically active Fe-N6 complexes (FeN6, [FeIII(porphyrin)(pyridine)2]). We expect the understanding of the FeN6 structure will pave the way towards new advanced Fe-N based electrocatalysts. The active FeNx sites in Fe/N/C catalysts were identified by electron microscopy and Mössbauer spectroscopy as the six-coordinate FeIII species [FeIII(porphyrin)(pyridine)2]. The results lead the way to target-specific synthesis of highly active and stable non-precious metal catalysts for oxygen reduction reaction. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Xie X.,CAS Dalian Institute of Chemical Physics | Shang P.,CAS Shenyang Institute of Metal Research | Liu Z.,CAS Shenyang Institute of Metal Research | Lv Y.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of Physical Chemistry C | Year: 2010

Cobalt hydroxycarbonate nanorods are prepared by precipitation of cobalt acetate with sodium carbonate in ethylene glycol. Structural and chemical analyses of the intermediate phases during the precipitation and aging process revealed that amorphous cobalt hydroxide acetate is formed at the initial stage where ethylene glycol acts as a simple solvent and a coordinating agent. With the slow addition of sodium carbonate, carbonate anions are gradually intercalated into the interlayers by replacing the acetate and hydroxyl anions. This anionexchange process induces a dissolution-recrystallization process in which ethylene glycol serves as a ratecontrolling agent, producing rod-like cobalt hydroxide carbonate. During the aging process, ethylene glycol gradually incorporates into the structure to replace the carbonate and acetate anions; the interlayer structure is collapsed, and the nanorod-shape turns into thin crimped sheets. Co3O4 nanorods with a diameter of about 10 nm and a length of 200-300 nm are then obtained by calcination of the nanorod-shaped cobalt hydroxycarbonate precursor. This spontaneous shape transformation from the precursor to the oxide is attributed to the unique thermal stability of the cobalt hydroxycarbonate nanorods with the presence of ethylene glycol and acetate anions in the interlayers. The Co3O 4 nanorods show a much superior catalytic activity for CO oxidation to the conventional spherical Co3O4 nanoparticles, clearly demonstrating the morphology-dependent nanocatalysis. Copyright © 2010 American Chemical Society.


Chang C.-R.,Tsinghua University | Yang X.-F.,Tsinghua University | Yang X.-F.,CAS Dalian Institute of Chemical Physics | Long B.,Tsinghua University | Li J.,Tsinghua University
ACS Catalysis | Year: 2013

To understand the catalytic mechanism of alcohol oxidation with molecular oxygen on bulk metallic gold catalysts, we have systematically studied the oxidative dehydrogenation of methanol on Au(111) using density functional theory. It is found that molecular oxygen can be activated via a hydroperoxyl (OOH) intermediate produced by abstracting a hydrogen atom from co-adsorbed methanol or water. Interestingly, extra water molecules significantly promote the hydrogen-transfer reactions between CH3OHO2 and H 2OO2 co-adsorbates, lowering the activation barrier of OOH formation from ∼0.90 to ∼0.45 eV. The formed OOH intermediate either directly reacts with methanol to produce formaldehyde or dissociates into adsorbed atomic oxygen and hydroxyl. Further calculations demonstrate that the oxidative dehydrogenation of methanol by OOH, atomic oxygen, and hydroxyl is extremely facile with low barriers between 0.06 and 0.30 eV. These results provide an explanation for the activation mechanism of molecular oxygen on bulk gold and reveal a possible pathway for alcohol oxidation with dioxygen. © 2013 American Chemical Society.


Gao Y.,CAS Beijing National Laboratory for Molecular | Gao Y.,CAS Dalian Institute of Chemical Physics | Hu G.,CAS Beijing National Laboratory for Molecular | Zhong J.,Soochow University of China | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2013

Thanks to nitrogen introduced into the layered carbon framework of graphite, the chemical reactivity of the carbon atoms was increased. N-doped graphitic catalysts generate reactive oxygen species and display excellent activity for hydrocarbon activation even at room temperature. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu B.,South-Central University for Nationalities | Zhang Z.,South-Central University for Nationalities | Zhao Z.K.,CAS Dalian Institute of Chemical Physics | Zhao Z.K.,Dalian National Laboratory for Clean Energy
Chemical Engineering Journal | Year: 2013

Microwave-assisted direct conversion of cellulose into HMF in ionic liquids catalyzed by ZrCl4 has been investigated in search of an efficient and environment-friendly process. Firstly, some representative metal chlorides were used to catalyze the conversion of glucose into HMF, and it was demonstrated that ZrCl4 was superior to other catalysts. Then direct conversion of cellulose into HMF was catalyzed by ZrCl4 under microwave irradiation (MI). Under optimal conditions, a high HMF yield up to 51.4% was obtained from cellulose in 3.5min under MI at 400W. Controllable experiments indicated that both ionic liquids, MI and ZrCl4 showed synergetic effects on the efficient conversion of cellulose into HMF. This work provides a meaningful method for the conversion of carbohydrates into fine chemicals. © 2012 Elsevier B.V.


Tian Z.,CAS Dalian Institute of Chemical Physics | Tian Z.,Dalian National Laboratory for Clean Energy | Kass S.R.,University of Minnesota
Chemical Reviews | Year: 2013

Carbanions are anions that have a carbon center with an unshared pair of electrons and a formal negative charge. Understanding the reactivity of carbanions is challenging because it depends upon the associated metal and is sensitive to additives, the solvent, temperature, and concentration. Complications in solution due to solvation, counterion effects, and aggregation have hindered our understanding of these species. As a result, the intrinsic reactivity and properties of isolated and truly free carbanions in the gas phase are of interest. Versatile synthetic strategies have been developed for the preparation of a wide variety of gaseous carbanions. This has enabled the reactivities and thermodynamic properties of many carbanions to be experimentally determined. Moreover, because the electron can be viewed as the simplest protecting group, the reactivities and energetics of neutral species such as radicals, biradicals, carbenes, and other fleetingly stable species also can be explored.


Lin R.,Dalian National Laboratory for Clean Energy | Ding Y.,Dalian National Laboratory for Clean Energy | Ding Y.,CAS Dalian Institute of Chemical Physics
Materials | Year: 2013

Considerable efforts have been devoted to extending the range of the elemental composition of mesoporous materials since the pioneering work of the M41S family of ordered mesoporous silica by Mobil researchers. The synthesis of transition metal-containing mesostructured materials with large surface area and high porosity has drawn great attention for its potential applications in acid and redox catalysis, photocatalysis, proton conducting devices, environmental restoration and so on. Thus, various transition metals-containing mesoporous materials, including transition metal-substituted mesoporous silicates, mesostructured transition metal oxides and transition metal phosphates (TMP), have been documented in the literature. Among these, mesostructured TMP materials are less studied, but possess some unique features, partly because of the easy and facile functionalization of PO4 and/or P-OH groups, rendering them interesting functional materials. This review first introduced the general synthesis strategies for manufacturing mesostructured TMP materials, as well as advantages and disadvantages of the respective method; then, we surveyed the ongoing developments of fabrication and application of the TMP materials in three groups on the basis of their components and application fields. Future perspectives on existing problems related to the present synthesis routes and further modifying of the functional groups for the purpose of tailoring special physical-chemical properties to meet wide application requirements were also provided in the last part. © 2013 by the authors; licensee MDPI, Basel, Switzerland.


Liu X.Y.,CAS Dalian Institute of Chemical Physics | Liu X.Y.,National Taiwan University | Wang A.,CAS Dalian Institute of Chemical Physics | Zhang T.,CAS Dalian Institute of Chemical Physics | Mou C.-Y.,National Taiwan University
Nano Today | Year: 2013

The metal-support interaction (MSI) plays an essential role in the catalysis by gold. We summarized the support effect on the catalysis by gold in this review. According to the reducibility of the oxide supports, we divide the supports into two categories: reducible metal-oxide (RMO) and irreducible oxide (IRO) supports. The catalytic mechanisms for low-temperature CO oxidation over RMO supported gold catalysts are discussed based on the recent progress on this topic and the key role of gold-support interface in the catalytic reactions is highlighted. To prolong the perimeters of the gold-support interfaces, one can both decrease the sizes of gold nanoparticles (GNPs) and tune the morphology of the support (e.g., shape, size, etc.). From the point of view of decreasing the size of both gold and the support simultaneously for maximizing the boundary of gold and the support, we classify the gold-based bimetallic catalysts into metal supported gold and inversely metal/RMO supported gold. The nanoporous gold (NPG) synthesized by dealloying bulk Au-Ag alloy can also be considered as an inversely Ag/AgOx supported gold catalyst. Thus, the traditional concept of support can be extended greatly. Finally, the strong metal-support interaction (SMSI) in the Au-based and Pt-based system has been compared to show the distinctive feature of gold catalysts. © 2013 Elsevier Ltd. All rights reserved.


Yang H.,Xiamen University | Wang Y.,Xiamen University | Lei J.,Xiamen University | Shi L.,CAS Dalian Institute of Chemical Physics | And 8 more authors.
Journal of the American Chemical Society | Year: 2013

Three novel bimetallic Au-Cu nanoclusters stabilized by a mixed layer of thiolate and phosphine ligands bearing pyridyl groups are synthesized and fully characterized by X-ray single crystal analysis and density functional theory computations. The three clusters have an icosahedral Au13 core face-capped by two, four, and eight Cu atoms, respectively. All face-capping Cu atoms in the clusters are triply coordinated by thiolate or pyridyl groups. The surface ligands control the exposure of Au sites in the clusters. In the case of the Au13Cu8 cluster, the presence of 12 2-pyridylthiolate ligands still leaves open space for catalysis. All the 3 clusters are 8-electron superatoms displaying optical gaps of 1.8-1.9 eV. The thermal decomposition studies suggest that the selective release of organic ligands from the clusters is possible. © 2013 American Chemical Society.


Meng Q.,CAS Dalian Institute of Chemical Physics | Meyer H.-D.,University of Heidelberg
Journal of Chemical Physics | Year: 2014

Employing the multilayer multiconfiguration time-dependent Hartree (ML-MCTDH) method in conjunction with the multistate multimode vibronic coupling Hamiltonian (MMVCH) model, we perform a full dimensional (9D) quantum dynamical study on the simplest Criegee intermediate, formaldehyde oxide, in five lower-lying singlet electronic states. The ultraviolet (UV) spectrum is then simulated by a Fourier transform of the auto-correlation function. The MMVCH model is built based on extensive MRCI(8e,8o)/aug-cc-pVTZ calculations. To ensure a fast convergence of the final calculations, a large number of ML-MCTDH test calculations is performed to find an appropriate multilayer separations (ML-trees) of the ML-MCTDH nuclear wave functions, and the dynamical calculations are carefully checked to ensure that the calculations are well converged. To compare the computational efficiency, standard MCTDH simulations using the same Hamiltonian are also performed. A comparison of the MCTDH and ML-MCTDH calculations shows that even for the present not-too-large system (9D here) the ML-MCTDH calculations can save a considerable amount of computational resources while producing identical spectra as the MCTDH calculations. Furthermore, the present theoretical \documentclass[12pt]{minimal}\begin{document}$\tilde{B}\:{}1A{\prime }\leftarrow \tilde{X}\:{}1A{\prime }$\end{document}B∼;1A′←X∼1A′ UV spectral band and the corresponding experimental measurements [J. M. Beames, F. Liu, L. Lu, and M. I. Lester, J. Am. Chem. Soc. 134, © 2014 AIP Publishing LLC.


Hou C.,Anhui Polytechnic University | Hou C.,CAS Dalian Institute of Chemical Physics
Computational and Theoretical Chemistry | Year: 2014

A quantum mechanical approach has been used to shed light on the antioxidative mechanism for scavenging OOH and OH radicals by norathyriol in the solution phase. Density functional theory (DFT) calculations at the B3LYP and UB3LYP/6-311+G(d,p) level are used to optimize norathyriol and its different radical forms. Analysis of the theoretical bond dissociation enthalpy (BDE) values for all OH sites of norathyriol in solution clearly shows the importance of the B-ring and the 6-OH and 7-OH groups in the antioxidant activity. We have also investigated the spin density of the radicals to determine the delocalization possibilities. The results of the calculations show that the oxidation of norathyriol by both the OOH and OH radical is an exothermic reaction. In all calculations solvent effects are considered using a polarized continuum model (PCM). © 2013 Elsevier B.V.


Su D.S.,CAS Shenyang Institute of Metal Research | Su D.S.,Fritz Haber Institute of the Max Planck Society | Sun G.,CAS Dalian Institute of Chemical Physics
Angewandte Chemie - International Edition | Year: 2011

Within reach: Newly developed nonprecious-metal catalysts can be used to produce inexpensive hydrogen fuel cells with performances approaching those of platinum-based systems. For example, the best non-Pt catalyst was prepared from a metal-organic framework consisting of zeolitic Zn II imidazolate which served as the host for the Fe and N precursors of the catalyst. The plot shows the volumetric current densities of the best non-Pt catalysts and the target value set by the U.S. DOE at 0.8 V). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Gao Y.,CAS Dalian Institute of Chemical Physics | Ma D.,CAS Beijing National Laboratory for Molecular | Hu G.,Exponent, Inc. | Zhai P.,CAS Beijing National Laboratory for Molecular | And 5 more authors.
Angewandte Chemie - International Edition | Year: 2011

Into the layer: Layered carbon-iron oxide nano-composites catalysts are very active in catalytic oxidation reactions. The size and structure of the iron oxide nanoparticles (blue in the TEM image) embedded in the layered carbon can be controlled very simply by changing the temperature of the synthesis reaction. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu S.,CAS Dalian Institute of Chemical Physics | Liu S.,Dalian National Laboratory for Clean Energy | Guo X.,CAS Changchun Institute of Optics and Fine Mechanics and Physics | Li M.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2011

Wiry solar cells: A solution-phase synthetic approach gave monocrystalline SnSe nanowires with a mean diameter of approximately 20.8 nm and a lattice distance of 0.575 nm (see HRTEM image). Hybrid solar cells based on a blend of these SnSe nanowires and poly(3-hexylthiophene) (P3HT) were fabricated. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Too P.C.,Nanyang Technological University | Noji T.,Tohoku University | Lim Y.J.,Nanyang Technological University | Li X.,CAS Dalian Institute of Chemical Physics | Chiba S.,Nanyang Technological University
Synlett | Year: 2011

A method for the synthesis of highly substituted pyri-dines from ,-unsaturated oximes and internal alkynes has been developed using [Cp*RhCl2]2-CsOPiv as the catalyst system. The present transformation is carried out by a redox-neutral sequence of vinylic C-H rhodation, alkyne insertion, and C-N bond formation of the putative vinyl rhodium intermediate with the oxime nitrogen, where the N-O bond of oxime derivatives could work as an internal oxidant to maintain the catalytic cycle. © Georg Thieme Verlag Stuttgart · New York.


Zhang Z.,CAS Dalian Institute of Chemical Physics | Zhang Z.,University of Chinese Academy of Sciences | Dong K.,CAS Dalian Institute of Chemical Physics | Dong K.,University of Chinese Academy of Sciences | And 2 more authors.
ChemSusChem | Year: 2011

A clean, facile, and environment-friendly catalytic method has been developed for the conversion of furfuryl alcohol into alkyl levulinates making use of the novel solid catalyst methylimidazolebutylsulfate phosphotungstate ([MIMBS]3PW12O40). The solid catalyst is an organic-inorganic hybrid material, which consists of an organic cation and an inorganic anion. A study for optimizing the reaction conditions such as the reaction time, the temperature and the catalyst loading has been performed. Under optimal conditions, a high n-butyl levulinate yield of up to 93 % is obtained. Furthermore, the kinetics of the reaction pathways and the mechanism for the alcoholysis of furfuryl alcohol are discussed. This method is environmentally benign and economical for the conversion of biomass-based derivatives into fine chemicals. Size zero waste: A clean, facile, and environment-friendly catalytic method has been developed for the conversion of furfuryl alcohol into alkyl levulinates, making use of the novel solid catalyst methylimidazolebutylsulfate phosphotungstate ([MIMBS]3PW 12O40). Under the optimal conditions, a high n-butyl levulinate yield of up to 93 % was obtained, with easy work-up procedures and minimal waste generation. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang Z.,CAS Dalian Institute of Chemical Physics | Zhang Z.,University of Chinese Academy of Sciences | Wang Q.,CAS Dalian Institute of Chemical Physics | Xie H.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
ChemSusChem | Year: 2011

Direct conversion of carbohydrates into 5-hydroxymethylfurfural (HMF) catalyzed by germanium(IV) chloride in ionic liquids has been investigated in search of an efficient and environmentally friendly process. Monosaccharides D-fructose and D-glucose, disaccharides sucrose and maltose, and even the polysaccharide cellulose were successfully converted into HMF with good yields under mild conditions (yield up to 92 % in 5 min in the case of fructose). The structure of ionic liquids, catalyst loading, reaction temperature and water content had noticeable effects on this catalytic system. Addition of 5 Å molecular sieves during the dehydration of glucose resulted in an increase in HMF yield from 38.4 % to 48.4 %. A mechanism for glucose conversion to HMF catalyzed by germanium(IV) chloride was proposed according to 13C NMR spectra obtained in situ under different conditions using D-glucose-2- 13C as the substrate. Ge whiz: Germanium(IV) chloride in ionic liquids catalyzes the direct conversion of carbohydrates into 5- hydroxymethylfurfural (HMF). The catalyst shows excellent activity for fructose dehydration, and a high yield of HMF up to 90 % is obtained in 5 min. This nontoxic catalytic system is also efficient for other carbohydrates such as glucose, sucrose, and even cellulose. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Luo Y.-C.,National Taiwan University | Liu Y.-H.,National Taiwan University | Hung Y.,National Taiwan University | Liu X.-Y.,CAS Dalian Institute of Chemical Physics | Mou C.-Y.,National Taiwan University
International Journal of Hydrogen Energy | Year: 2013

Mesoporous silica supported cobalt boride (Co-B) catalysts are rationally designed for hydrogen generation in ammonia-borane hydrolysis reactions under ambient conditions. Cobalt boride catalysts are supported on three different mesoporous silica, including beta-zeolite seeded MCM-41 (Co@M41S) and traditional MCM-41 (Co@M41T) via chemical adsorption onto functionalized surface with 3-trihydroxysilylpropylmethylphosphonate (THPMP), and one-step co-precipitation into mesoporous silica framework (Co@M41C). Our preparation strategies provide two insights to the reactions: first, cobalt oxide species are intrinsically deposited as ultra-small nanoparticles (<2 nm) on mesoporous silica supports; subsequently the nanoparticles are converted to active Co-B catalysts by reduction with sodium borohydride (SB). Three catalysts exhibit significant differences in catalytic reactivities with hydrogen production rates ranked in an order of Co@M41S > Co@M41T > Co@M41C. Detailed analysis of the coordination environments from in situ X-ray absorption spectroscopy (XAS) results confirm reducibility in SB. Amorphous nature of Co-B catalysts are responsible for efficient catalytic activity in Co@M41S and Co@M41T. Ammonia temperature programmed desorption (NH3-TPD) demonstrates support acidity that correlates to the degree of high dispersity and effective reducibility to Co-B. Effects from catalyst sizes, reducibility in SB treatment and surface acidity are studied in detail to compare catalytic reactivities among three types of supports. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.


Zhang Z.,South-Central University for Nationalities | Zhang Z.,CAS Dalian Institute of Chemical Physics | Liu B.,South-Central University for Nationalities | Zhao Z.,CAS Dalian Institute of Chemical Physics | Zhao Z.,Dalian National Laboratory for Clean Energy
Polymer Degradation and Stability | Year: 2012

A novel method for cellulose hydrolysis catalyzed by mineral acids have been developed in organic electrolyte solutions at 70°C under atmosphere pressure without pretreatment. Several reaction parameters including reaction time, temperature, catalyst loading and the ratio of ionic liquids to organic solvents have been evaluated and optimized. Under optimal conditions, the maximum total reducing sugars (TRS) yield in 68.8% and glucose yield in 39.2% were obtained in 1.0 g NMP/3.0 g [Bmim]Cl system at 70°C. Due to the low temperature of cellulose hydrolysis, this method shows a promising potential as an energy-efficient and cost-effective approach for the biorefinery of lignocellulosic biomass. © 2012 Elsevier Ltd. All rights reserved.


Zeng Z.-H.,CAS Dalian Institute of Chemical Physics | Da Silva J.L.F.,University of Sao Paulo | Li W.-X.,CAS Dalian Institute of Chemical Physics
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

The origin of the unique geometry for nitric oxide (NO) adsorption on Pd(111) and Pt(111) surfaces as well as the effect of temperature were studied by density functional theory calculations and ab initio molecular dynamics at finite temperature. We found that at low coverage, the adsorption geometry is determined by electronic interactions, depending sensitively on the adsorption sites and coverages, and the effect of temperature on geometries is significant. At coverage of 0.25 monolayer (ML), adsorbed NO at hollow sites prefer an upright configuration, while NO adsorbed at top sites prefer a tilting configuration. With increase in the coverage up to 0.50 ML, the enhanced steric repulsion lead to the tilting of hollow NO. We found that the tilting was enhanced by the thermal effects. At coverage of 0.75 ML with p (2×2) -3NO (fcc+hcp+top) structure, we found that there was no preferential orientation for tilted top NO. The interplay of the orbital hybridization, thermal effects, steric repulsion, and their effects on the adsorption geometries were highlighted at the end. © 2010 The American Physical Society.


Liu X.,CAS Dalian Institute of Chemical Physics | Liu X.,National Taiwan University | Wang A.,CAS Dalian Institute of Chemical Physics | Li L.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Journal of Catalysis | Year: 2011

Au-Cu bimetallic nanoparticles supported on SBA-15 have been reported to be much more active in CO oxidation than the corresponding monometallic counterparts in our previous work. In this work, in situ techniques including XRD, EPR, XANES, and FT-IR were employed to reveal the structural changes of the Au-Cu bimetallic particles during different pretreatment and reaction conditions, and to clarify the essence of the synergistic effect between gold and copper. The results showed that gold remained as Au0 in any treatment conditions, while copper was very sensitive to the treatment temperature and atmosphere. The freshly reduced catalyst was a mixture of Au3Cu1 intermetallic phase and Cu2O amorphous phase. In CO oxidation, the Au3Cu1 intermetallic phase was segregated into a gold core decorated with tiny CuOx patches, and CO adsorbed on Au0 reacted with active oxygen provided by the neighboring CuOx, thus enhancing greatly the activity for CO oxidation. © 2010 Elsevier Inc. All rights reserved.


He C.,Sun Yat Sen University | Liang Y.,Sun Yat Sen University | Fu R.,Sun Yat Sen University | Wu D.,Sun Yat Sen University | And 2 more authors.
Journal of Materials Chemistry | Year: 2011

A nanopores array in ordered mesoporous materials matters significantly to the reactant molecules arriving at the active catalytic sites in the interior of the nanostructure. However, how this effect works in the case of electrocatalysis needs investigating. We present that the nanopores array of carbon supports plays a significant role in determining Pt's accessibility and electroactivity. The ordered mesoporous carbons with interconnected pore channels (CMK-3) provide Pt nanoparticles with more than one order of magnitude superior Pt utilization efficiency and alcohol electrooxidation activity to those with isolated pore channels by carbon wall (FDU-15). This becomes more prominent in the case of the electrooxidation of isopropanol with a bigger molecular size and lower polarization. These findings indicate the significant role of nanoarchitectures in Pt's accessibility and electroactivity. It is possible to extend this concept to the other fine chemistry typical of surface activity and facile mass transport of molecules. © 2011 The Royal Society of Chemistry.


Wu C.,CAS Dalian Institute of Chemical Physics | Cheng H.-M.,CAS Shenyang Institute of Metal Research
Journal of Materials Chemistry | Year: 2010

The development of hydrogen storage materials with high performance has been attracting considerable attention in recent years. Magnesium hydride, alanates, borohydrides and ammonia borane are the most promising candidates due to their high hydrogen capacity, but each type has its own shortcomings. In this short feature article, we highlight the current advances in the property enhancement of metal hydrides and complex hydrides by incorporating carbon materials, particularly carbon nanostructures such as nanotubes. Carbon with a small curvature radius exhibits prominent "catalytic" effect in conventional metal hydrides and complex hydrides. The smaller the curvature radius, the stronger the electronic affinity, and the stronger the interaction of carbon with hydrogen, which leads to a change of hydrogen release/combination energy, and consequently improving the de-/rehydrogenation kinetics. Meanwhile, the nanoconfinement effects of carbon scaffolds on all above hydrides were also discussed. © 2010 The Royal Society of Chemistry.


Qiao B.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | Yang X.,Tsinghua University | Allard L.F.,Oak Ridge National Laboratory | And 6 more authors.
Nature Chemistry | Year: 2011

Platinum-based heterogeneous catalysts are critical to many important commercial chemical processes, but their efficiency is extremely low on a per metal atom basis, because only the surface active-site atoms are used. Catalysts with single-atom dispersions are thus highly desirable to maximize atom efficiency, but making them is challenging. Here we report the synthesis of a single-atom catalyst that consists of only isolated single Pt atoms anchored to the surfaces of iron oxide nanocrystallites. This single-atom catalyst has extremely high atom efficiency and shows excellent stability and high activity for both CO oxidation and preferential oxidation of CO in H2. Density functional theory calculations show that the high catalytic activity correlates with the partially vacant 5d orbitals of the positively charged, high-valent Pt atoms, which help to reduce both the CO adsorption energy and the activation barriers for CO oxidation. © 2011 Macmillan Publishers Limited. All rights reserved.


Ma X.,CAS Dalian Institute of Chemical Physics | Zhang H.,CAS Dalian Institute of Chemical Physics | Sun C.,Dalian RONGKEPOWER Co. | Zou Y.,Dalian RONGKEPOWER Co. | Zhang T.,Dalian RONGKEPOWER Co.
Journal of Power Sources | Year: 2012

Electrolyte flow rate is a key factor that affects the performance of vanadium redox flow battery (VRFB). A kilo-watt class VRFB system is fabricated to investigate the effects of electrolyte flow rate on the performance of VRFB. The experiments show that the capacity increases, but the system efficiency decreases with the increase of electrolyte flow rate. An optimal strategy of electrolyte flow rate is proposed to improve the system efficiency and keep the high capacity simultaneously, which is corresponding to optimize the electrolyte flow rate at different stages of charge and discharge processes. The results show that the system efficiency can be improved as high as 8% when keeping high capacity simultaneously. © 2011 Elsevier B.V. All rights reserved.


Zheng Q.,CAS Dalian Institute of Chemical Physics | Zheng Q.,Dalian University of Technology | Zheng Q.,University of Chinese Academy of Sciences | Zhang H.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Applied Energy | Year: 2014

A three-dimensional model for thermal analysis has been developed to gain a better understanding of thermal behavior in a vanadium flow battery (VFB). The model is based on a comprehensive description of mass, momentum, charge and energy transport and conservation, combining with a global kinetic model for reactions involving all vanadium species. The emphasis in this paper is placed on the heat losses inside a cell. A quasi-static behavior of temperature and the temperature spatial distribution were characterized via the thermal model. The simulations also indicate that the heat generation exhibits a strong dependence on the applied current density. The reaction rate and the over potential rise with an increased applied current density, resulting in the electrochemical reaction heat rises proportionally and the activation heat rises at a parabolic rate. Based on the Ohm's law, the ohmic heat rises at a parabolic rate when the applied current density increases. As a result, the determining heat source varies when the applied current density changes. While the relative contribution of the three types of heat is dependent on the cell materials and cell geometry, the regularities of heat losses can also be attained via the model. In addition, the electrochemical reaction heat and activation heat have a lack of sensitivity to the porosity and flow rate, whereas an obvious increase of ohmic heat has been observed with the rise of the porosity. A lower porosity or a faster flow shows a better uniformity of temperature distribution in a VFB. Thus, the model proposed in this paper shows good prospect in heat and temperature management for a VFB aiming at eliminating any crisis of internal heat accumulation. © 2013 Elsevier Ltd.


Chen J.,Shandong Jiaotong University | Wang J.,CAS Shanghai Institute of Materia Medica | Zhu W.,CAS Shanghai Institute of Materia Medica | Li G.,CAS Dalian Institute of Chemical Physics
Journal of Computer-Aided Molecular Design | Year: 2013

Molecular dynamics (MD) simulations followed by principal component analysis were performed to study the conformational change of MDM2 induced by p53 and two inhibitor (P4 and MI63a) bindings. The results show that the hydrophobic cleft of MDM2 is very flexible and adaptive to different structural binding partners. The cleft tends to become wider and more stable as MDM2 binds to the three binding partners, while unbound MDM2 shows a narrower and pretty flexible cleft, which agrees with recent experimental data and theoretical studies. It was also found that the binding of P4 and p53 stabilizes the motion of the loop L2 linking the helix α2 and β strand (β3), but the presence of MI63a makes the motion of L2 disordered. In addition, the binding free energies of the three partners to MDM2 were calculated using molecular mechanics generalized Born surface area to explain the binding modes of these three partners to MDM2. This study will be helpful not only for better understanding the functional, concerted motion of MDM2, but also for the rational design of potent anticancer drugs targeting the p53-MDM2 interaction. © 2013 Springer Science+Business Media Dordrecht.


Xu Z.,CAS Dalian Institute of Chemical Physics | Xu Z.,University of Chinese Academy of Sciences | Zhang H.,CAS Dalian Institute of Chemical Physics | Zhong H.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Applied Catalysis B: Environmental | Year: 2012

Carbon supported Pt (Pt/C) with various average particle sizes ranging from sub 3. nm to 6.5. nm were in situ prepared and characterized at the cathode of proton exchange membrane fuel cells (PEMFCs). A clear Pt particle size effect on both the catalytic activity for oxygen reduction reaction (ORR) and the durability of the electrocatalyst was revealed. With the Pt particle size increase, both the surface specific activity and the electrochemical stability of Pt/C improved; however, the mass specific activity of Pt/C is balanced by the electrochemical surface area loss. The reduced occupation of corner and edge atoms on the Pt surface during the Pt particle size increase is believed to weaken the adsorption of the oxygenated species on Pt, and thereafter releases more available active sites for ORR and also renders the Pt surface a stronger resistance against potential cycling. It is therefore proposed that by designing the Pt microstructure with more face atoms on the surface, cathode electrocatalyst with both improved activity and enhanced durability would be developed for PEMFCs. © 2011 Elsevier B.V.


Ren H.,CAS Dalian Institute of Chemical Physics | Girisuta B.,Institute of Chemical and Engineering Sciences, Singapore | Zhou Y.,CAS Dalian Institute of Chemical Physics | Liu L.,Dalian University of Technology
Carbohydrate Polymers | Year: 2015

Cellulose depolymerization to levulinic acid (LA) was catalyzed by acidic ionic liquids (ILs) selectively and recyclably under hydrothermal conditions. The effects of reaction temperature, time, water amount and cellulose intake were investigated. Dilution effect becomes more pronounced at lower cellulose intake, dramatically improving the yield of LA to 86.1%. A kinetic model has been developed based on experimental data, whereby a good fit was obtained and kinetic parameters were derived. The relationships between IL structure, polymeric structure and depolymerization efficiency were established, shedding light on the in-depth catalytic mechanism of IL, inclusive of acidity and hydrogen bonding ability. The LA product can be readily separated through extraction by methyl isobutyl ketone (MIBK) and IL can be reused over five cycles without loss of activity. This environmentally friendly methodology can be applied to selective production of LA from versatile biomass feedstocks, including cellulose and derivatives, glucose, fructose and HMF. © 2014, Elsevier Ltd. All rights reserved.


Ren X.-F.,Jilin University | Ren A.-M.,Jilin University | Feng J.-K.,Jilin University | Zhou X.,CAS Dalian Institute of Chemical Physics
Organic Electronics: physics, materials, applications | Year: 2010

Density functional theory (DFT) calculations have been carried out on the electronicstructures, electronic spectra, carrier injection and transport properties of a series ofporphyrin derivatives, 5,15-di(R)porphyrin, 5,10,15,20-tetra(R)porphyrin, and Zn-5,10,15,20-tetra(R)- porphyrin, namely, DCP, TCP, and ZCP (where R = carbazole); DMP, TMP, and ZMP (where R = N,N-dimethyl-phenyl); DQP, TQP, and ZQP (where R = 2,3,6,7-tetrahydro-1H, 5Hbenzo[ ij]puinolizine). The through-bond (TB) energy transfer process in these porphyrin derivatives has been verified by three aspects of characters, i.e. electronic structures, Dexter-type and Förster-type energy transfer. Moreover, the reasons for their high efficiency as red emitting materials have been revealed by the investigations of the ionization potential (IP), electron affinity (EA), reorganization energy (λ), and exciton binding energy (Eb). These structure-property relationships provide a valuable guide for the design and synthesis of highly efficient red light-emitting materials based on porphyrin derivatives. © 2010 Elsevier B.V.


Zhao C.,Jilin University | Ma W.,CAS Dalian Institute of Chemical Physics | Sun W.,Jilin University | Na H.,Jilin University
Journal of Applied Polymer Science | Year: 2014

This article presented the synthetic and preparation route of quaternary ammonium functionalized anion exchange membranes (AEMs), which were derived from an engineering plastics polymer, poly(arylene ether sulfone) with 3,3′,5,5′-tetramethyl-4,4′-dihydroxybipheny moiety (PAES-TM). The benzylmethyl groups on the main-chain of PAES-TM were converted to the bromomethyl groups via a radical reaction, thereby avoiding complicated chloromethylation, which required carcinogenic reagents. The chemical structure of the bromomethylated PAES was characterized by 1H NMR spectrum. Following a homogeneous quaternization with trimethylamine in the solution, a series of flexible and tough membranes were obtained by a solution casting and anion exchange process. The ion exchange capacity values were ranging from 1.03 to 1.37 meq g-1. The properties of the membranes, including water uptake, hydroxide conductivity, and methanol permeability were evaluated in detail. The AEM showed a high conductivity above 10-2 S cm-1 at room temperature and extremely low methanol permeability of 4.16-4.94 × 10-8 cm2 s-1. The high hydroxide conductivity of TMPAES-140-NOH could be attributed to the nano-scale phase-separated morphology in the membrane, which was confirmed by their transmission electron microscopy images. © 2013 Wiley Periodicals, Inc.


Lin J.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | Qiao B.,CAS Dalian Institute of Chemical Physics | Liu X.,CAS Dalian Institute of Chemical Physics | And 7 more authors.
Journal of the American Chemical Society | Year: 2013

High specific activity and cost effectiveness of single-atom catalysts hold practical value for water gas shift (WGS) reaction toward hydrogen energy. We reported the preparation and characterization of Ir single atoms supported on FeOx (Ir1/FeOx) catalysts, the activity of which is 1 order of magnitude higher than its cluster or nanoparticle counterparts and is even higher than those of the most active Au- or Pt-based catalysts. Extensive studies reveal that the single atoms accounted for ∼70% of the total activity of catalysts containing single atoms, subnano clusters, and nanoparticles, thus serving as the most important active sites. The Ir single atoms seem to greatly enhance the reducibility of the FeOx support and generation of oxygen vacancies, leading to the excellent performance of the Ir1/FeOx single-atom catalyst. The results have broad implications on designing supported metal catalysts with better performance and lower cost. © 2013 American Chemical Society.


Yang X.-F.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | Qiao B.,CAS Dalian Institute of Chemical Physics | Li J.,Tsinghua University | And 3 more authors.
Accounts of Chemical Research | Year: 2013

Supported metal nanostructures are the most widely used type of heterogeneous catalyst in industrial processes. The size of metal particles is a key factor in determining the performance of such catalysts. In particular, because low-coordinated metal atoms often function as the catalytically active sites, the specific activity per metal atom usually increases with decreasing size of the metal particles. However, the surface free energy of metals increases significantly with decreasing particle size, promoting aggregation of small clusters. Using an appropriate support material that strongly interacts with the metal species prevents this aggregation, creating stable, finely dispersed metal clusters with a high catalytic activity, an approach industry has used for a long time. Nevertheless, practical supported metal catalysts are inhomogeneous and usually consist of a mixture of sizes from nanoparticles to subnanometer clusters. Such heterogeneity not only reduces the metal atom efficiency but also frequently leads to undesired side reactions. It also makes it extremely difficult, if not impossible, to uniquely identify and control the active sites of interest.The ultimate small-size limit for metal particles is the single-atom catalyst (SAC), which contains isolated metal atoms singly dispersed on supports. SACs maximize the efficiency of metal atom use, which is particularly important for supported noble metal catalysts. Moreover, with well-defined and uniform single-atom dispersion, SACs offer great potential for achieving high activity and selectivity.In this Account, we highlight recent advances in preparation, characterization, and catalytic performance of SACs, with a focus on single atoms anchored to metal oxides, metal surfaces, and graphene. We discuss experimental and theoretical studies for a variety of reactions, including oxidation, water gas shift, and hydrogenation. We describe advances in understanding the spatial arrangements and electronic properties of single atoms, as well as their interactions with the support. Single metal atoms on support surfaces provide a unique opportunity to tune active sites and optimize the activity, selectivity, and stability of heterogeneous catalysts, offering the potential for applications in a variety of industrial chemical reactions. © 2013 American Chemical Society.


Zhang X.,CAS Dalian Institute of Chemical Physics | Zhang X.,University of Jinan | Wang F.,CAS Dalian Institute of Chemical Physics | Qi Z.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Organic Letters | Year: 2014

Rhodium(III)-catalyzed arylation of arenes bearing a chelating group has been realized via a redox-economy process using 4-hydroxycyclohexa-2,5-dienones as the arylating reagents, leading to the synthesis of 3-arylated phenols. This redox-neutral process proceeds via a C-H activation pathway with rearomatization being the driving force. © 2014 American Chemical Society.


Chen J.,Jilin University | Song G.,CAS Dalian Institute of Chemical Physics | Pan C.-L.,CAS Dalian Institute of Chemical Physics | Li X.,CAS Dalian Institute of Chemical Physics
Organic Letters | Year: 2010

[RhCp*Cl2]2 (1-2 mol %) can catalyze the oxidative coupling of N-aryl-2-aminopyridines with alkynes and arylates to give N-(2-pyridyl)indoles and N-(2-pyridyl)quinolones, respectively, using Cu(OAc)2 as an oxidant. Coupling with styrenes gave mono- and/or disubstituted olefination products. © 2010 American Chemical Society.


Zhu J.,Dalian Polytechnic University | Guo X.,Dalian Polytechnic University | Fu S.,Dalian Polytechnic University | Zhang X.,CAS Dalian Institute of Chemical Physics | Liang X.,CAS Dalian Institute of Chemical Physics
Journal of Pharmaceutical and Biomedical Analysis | Year: 2010

Steroidal saponins are the major bioactive constituents of Dioscorea zingiberensis C. H. Wright (D. zingiberensis). In this work, ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS/MS) was applied to the separation and characterization of steroidal saponins in crude extracts from D. zingiberensis. The results showed that fragment ions from glycosidic and cross-ring cleavages gave a wealth of structural information related to aglycone skeletons, sugar types and the sequence of sugar units. According to the summarized fragmentation patterns, identification of steroidal saponins from D. zingiberensis could be fulfilled, even when reference standards were unavailable. As a result, a total of thirty-one saponins with five aglycone skeletons, including fourteen new trace saponins, were identified or tentatively elucidated in crude extracts from D. zingiberensis based on their retention times, the mass spectrometric fragmentation patterns, and MS and MS/MS data. © 2010 Elsevier B.V.


Su P.,CAS Dalian Institute of Chemical Physics | Su P.,University of Chinese Academy of Sciences | Xiao H.,University of Chinese Academy of Sciences | Xiao H.,Dalian National Laboratory for Clean Energy | And 6 more authors.
Chemical Science | Year: 2013

Nitrogen-doped carbon nanotubes (NCNTs) have been successfully synthesized via the direct solid pyrolysis of Zn-Fe-ZIF and the N content, N doped state, diameter and formation temperature of the NCNTs can be finely tuned by mixing Zn-Fe-ZIF with proper amounts of dicyandiamide (DCDA). DCDA serves as the extra nitrogen supplier and favors the formation of NCNTs at relatively low temperature due to its inducing effect for graphitic structure. The synthesized NCNTs, with iron species and high amounts of graphitic N, exhibit higher catalytic activity than commercial Pt/C as oxygen reduction electrocatalysts in alkaline solution. © 2013 The Royal Society of Chemistry.


Xu B.,CAS Dalian Institute of Chemical Physics | Xu B.,University of Tennessee Health Science Center | Schones D.E.,Beckman Research Institute | Wang Y.,University of Memphis | And 2 more authors.
PLoS ONE | Year: 2013

Scanning through genomes for potential transcription factor binding sites (TFBSs) is becoming increasingly important in this post-genomic era. The position weight matrix (PWM) is the standard representation of TFBSs utilized when scanning through sequences for potential binding sites. However, many transcription factor (TF) motifs are short and highly degenerate, and methods utilizing PWMs to scan for sites are plagued by false positives. Furthermore, many important TFs do not have well-characterized PWMs, making identification of potential binding sites even more difficult. One approach to the identification of sites for these TFs has been to use the 3D structure of the TF to predict the DNA structure around the TF and then to generate a PWM from the predicted 3D complex structure. However, this approach is dependent on the similarity of the predicted structure to the native structure. We introduce here a novel approach to identify TFBSs utilizing structure information that can be applied to TFs without characterized PWMs, as long as a 3D complex structure (TF/DNA) exists. This approach utilizes an energy function that is uniquely trained on each structure. Our approach leads to increased prediction accuracy and robustness compared with those using a more general energy function. The software is freely available upon request. © 2013 Xu et al.


Yang D.,CAS Dalian Institute of Chemical Physics | Yang D.,University of Chinese Academy of Sciences | Zhou L.,CAS Dalian Institute of Chemical Physics | Zhou L.,University of Chinese Academy of Sciences | And 4 more authors.
Chemical Communications | Year: 2012

We demonstrate O 2 plasma treated graphene oxides with a work function of 5.2 eV as a high performance hole transport layer in organic solar cells. The high transparency and high work function simultaneously increase short circuit current, threshold voltage and fill factor, resulting in a 30% increase in cell efficiency. © 2012 The Royal Society of Chemistry.


Xu Y.,Nankai University | Jia X.-H.,CAS Institute of Automation | Yin X.-B.,Nankai University | He X.-W.,Nankai University | And 2 more authors.
Analytical Chemistry | Year: 2014

Magnetic resonance imaging (MRI) is used extensively for clinical diagnoses. It is critical to design and develop highly efficient MR contrast agents with simple preparation procedure, low toxicity, and high biocompatibility. Here, we report a carbon quantum dots (CQDs)-stabilized gadolinium hybrid nanoprobe (Gd-CQDs) prepared via a one-pot hydrothermal treatment of the mixture of citrate acid, ethanediamine, and GdCl3 at 200°C for 4 h. In vitro and in vivo tests confirmed their low toxicity and high biocompatibility. Gd-CQDs were observed to have a higher MR response than gadopentetic acid dimeglumine (Gd-DTPA) because of their high Gd content and hydrophilicity. Moreover, the fluorescence of CQDs was remained in Gd-CQDs. The in vivo MR and fluorescence dual-modality imaging of Gd-CQDs was confirmed with zebrafish embryo and mice as models. The modification of Gd-CQDs with arginine-glycine-aspartic acid (RGD) tripeptide provided a high affinity to U87 cancer cells for targeted imaging. Whereas the MR response showed a depth penetration and spatial visualization, fluorescence revealed the fine distribution of Gd-CQDs in tissues because of its high resolution and sensitivity. We found that Gd-CQDs distributed in the tissues in a heterogeneous mode: they entered into the tissue cells but were observed less in the extracellular matrix. The MR and fluorescence dual-modality imaging of Gd-CQDs makes them a potential contrast agent for clinic applications because of their simple preparation procedure, ease of functionalization, high contrast efficiency, low toxicity, and high biocompatibility. (Figure Presented). © 2014 American Chemical Society.


Gao K.,CAS Dalian Institute of Chemical Physics | Yu C.-B.,CAS Dalian Institute of Chemical Physics | Li W.,Rutgers University | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics | Zhang X.,Rutgers University
Chemical Communications | Year: 2011

Highly enantioselective hydrogenation of seven-membered cyclic imines, substituted dibenzo[b,f][1,4]oxazepines, was achieved, with up to 94% ee, by using the [Ir(COD)Cl]2/(S)-Xyl-C3*-TunePhos complex as the catalyst in the presence of morpholine-HCl. © 2011 The Royal Society of Chemistry.


Wicker B.F.,Indiana University Bloomington | Fan H.,Indiana University Bloomington | Fan H.,CAS Dalian Institute of Chemical Physics | Hickey A.K.,Indiana University Bloomington | And 5 more authors.
Journal of the American Chemical Society | Year: 2012

The anilide-methyl complex (PNP)Sc(NH[DIPP])(CH3) (1) [PNP - = bis(2-diisopropylphosphino-4-tolyl)amide, DIPP = 2,6-diisopropylphenyl] eliminates methane (kavg = 5.13 × 10-4 M-1s-1 at 50 °C) in the presence of pyridine to generate the transient scandium imido (PNP)Sc=[DIPP](NC 5H5) (A-py), which rapidly activates the C-H bond of pyridine in 1,2-addition fashion to form the stable pyridyl complex (PNP)Sc(NH[DIPP])(η2-NC5H4) (2). Mechanistic studies suggest the C-H activation process to be second order overall: first order in scandium and first order in substrate (pyridine). Pyridine binding precedes elimination of methane, and α-hydrogen abstraction is overall-rate-determining [the kinetic isotope effect (KIE) for 1-d1 conversion to 2 was 5.37(6) at 35 C and 4.9(14) at 50 C] with activation parameters ΔH‡ = 17.9(9) kcal/mol and ΔS‡ = -18(3) cal/(mol K), consistent with an associative-type mechanism. No KIE or exchange with the anilide proton was observed when 1-d3 was treated with pyridine or thermolyzed at 35 or 50 °C. The post-rate-determining step, C-H bond activation of pyridine, revealed a primary KIE of 1.1(2) at 35 °C for the intermolecular C-H activation reaction in pyridine versus pyridine-d5. Complex 2 equilibrated back to the imide A-py slowly, as the isotopomer (PNP)Sc(ND[DIPP])(η2-NC5H4) (2-d 1) converted to (PNP)Sc(NH[DIPP])(η2-NC 5H3D) over 9 days at 60 °C. Molecular orbital analysis of A-py suggested that this species possesses a fairly linear scandium imido motif (169.7 ) with a very short Sc-N distance of 1.84 Å. Substituted pyridines can also be activated, with the rates of C-H activation depending on both the steric and electronic properties of the substrate. © 2012 American Chemical Society.


Liu Y.,Harbin Institute of Technology | Liu Y.,CAS Dalian Institute of Chemical Physics | Liu H.,Harbin Institute of Technology | Ma J.,Harbin Institute of Technology | Li J.,Harbin Institute of Technology
Electrochimica Acta | Year: 2011

The present work focused on the investigation of electrochemical properties of cerium doped lead dioxide anode, i.e. Ti/Ce-PbO2. SEM, AFM, XRD and XPS were used to characterize the morphology, crystal structure and elemental states of the modified anode. Electrochemical impedance spectroscopy (EIS) was also utilized to study the electrochemical property of Ti/Ce-PbO 2. The electrochemical activity of the Ti/Ce-PbO2 anode was investigated by means of bulk electrolysis and compared with that of a PbO2 anode. The accelerated life test and oxidants determination were also conducted. The results indicated that the incorporation of cerium improved the electrocatalytic activity and stability of PbO2 anode. The service life of Ti/Ce-PbO2 electrode was much longer than that of traditional lead dioxide electrode. The electrochemical activity obtained from degradation of o-nitrophenol (o-NP) outperformed the traditional lead dioxide electrode as well. The Ti/Ce-PbO2 electrode is considered a promising anode for the treatment of organic pollutants. © 2010 Elsevier Ltd. All rights reserved.


Wang D.-S.,CAS Dalian Institute of Chemical Physics | Chen Q.-A.,CAS Dalian Institute of Chemical Physics | Li W.,Rutgers University | Yu C.-B.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of the American Chemical Society | Year: 2010

The first highly enantioselective hydrogenation of simple indoles was developed with a Brnsted acid as an activator to form the iminium intermediate in situ, which was hydrogenated using Pd(OCOCF3)2/(R)-H8- BINAP catalyst system with up to 96% ee. The present method provides an efficient route to enantioenriched 2-substituted and 2,3-disubstituted indolines. © 2010 American Chemical Society.


Yu C.,Jiangxi University of Science and Technology | Xu H.,CAS Dalian Institute of Chemical Physics
Separation and Purification Technology | Year: 2011

An efficient palladium membrane was employed for hydrogen separation in lab-scale membrane reactor during the process of catalytic dehydrogenation of ethylbenzene to styrene. Compared with the conventional fixed bed reactor, the effects of reaction conditions including pressure, space velocity and temperatures on the ethylbenzene conversion and selectivity to styrene in the membrane reactor were investigated. It was found that the efficient removal of hydrogen in the membrane reactor could significantly increase the ethylbenzene conversion without at the expense of styrene selectivity. Under the optimal reaction conditions, 11.3% enhancement in yield to styrene was obtained in the membrane reactor. © 2011 Elsevier B.V. All rights reserved.


Yin Z.,CAS Dalian Institute of Chemical Physics | Zhou W.,Lehigh University | Gao Y.,CAS Beijing National Laboratory for Molecular | Ma D.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Chemistry - A European Journal | Year: 2012

Monodisperse bimetallic Pd-Cu nanoparticles with controllable size and composition were synthesized by a one-step multiphase ethylene glycol (EG) method. Adjusting the stoichiometric ratio of the Pd and Cu precursors afforded nanoparticles with different compositions, such as Pd 85-Cu 15, Pd 56-Cu 44, and Pd 39-Cu 61. The nanoparticles were separated from the solution mixture by extraction with non-polar solvents, such as n-hexane. Monodisperse bimetallic Pd-Cu nanoparticles with narrow size-distribution were obtained without the need for a size-selection process. Capping ligands that were bound to the surface of the particles were removed through heat treatment when the as-prepared nanoparticles were loaded onto a Vulcan XC-72 carbon support. Supported bimetallic Pd-Cu nanoparticles showed enhanced electrocatalytic activity towards methanol oxidation compared with supported Pd nanoparticles that were fabricated according to the same EG method. For a bimetallic Pd-Cu catalyst that contained 15% Cu, the activity was even comparable to the state-of-the-art commercially available Pt/C catalysts. A STEM-HAADF study indicated that the formation of random solid-solution alloy structures in the bimetallic Pd 85-Cu 15/C catalysts played a key role in improving the electrochemical activity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Lin H.,CAS Dalian Institute of Chemical Physics | Lin H.,University of Chinese Academy of Sciences | Ou J.,CAS Dalian Institute of Chemical Physics | Zhang Z.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
Analytical Chemistry | Year: 2012

A simple single-step thermal-treatment "one-pot" approach for the preparation of organic-silica hybrid capillary monolithic columns is described. In this improved method, the cross-linker vinyltrimethoxysilane (VTMS) was replaced by 3-methacryloxypropyltrimethoxysilane (γ-MAPS), which is more active in polymerization reactions, and only one thermal treatment step was required in the preparation of hybrid monoliths. Two zwitterionic organic-silica monolithic columns were successfully synthesized by using [2-(methacryloyloxy) ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MSA) and 2- methacryloyloxyethyl phosphorylcholine (MPC) as the organic monomers. The effects of the tetramethoxysilane (TMOS)/γ-MAPS molar ratio, content of monomer, composition of porogenic solvent, and reaction temperature on the morphologies of the hybrid monoliths were investigated. The MSA-silica and MPC-silica hybrid monolithic columns exhibited good permeability and good mechanical stability. The monolithic columns were used for the separation of polar compounds by capillary hydrophilic-interaction chromatography (cHILIC). A typical HILIC retention mechanism was observed at higher organic solvent contents (>50% ACN). The MSA monoliths were further investigated in the separation of various neutral, basic, and acidic analytes, as well as small peptides, by capillary liquid chromatography (cLC), and high efficiency and satisfactory reproducibility were achieved. In addition, the analysis of a tryptic digest of bovine serum albumin (BSA) by cLC tandem mass spectrometry (cLC-MS/MS) with an MSA monolith further demonstrated its potential in the separation of biological samples. © 2012 American Chemical Society.


Xiahou C.,University of Manchester | Connor J.N.L.,University of Manchester | Zhang D.H.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

State-of-the-art differential cross sections (DCSs) have been reported by Wang et al. [Proc. Nat. Acad. Sci. (U.S.), 2008, 105, 6227] for the state-to-state F + H2 → FH + H reaction using fully quantum-state-selected crossed molecular beams. We theoretically analyze the angular scattering of this reaction, in order to quantitatively understand the physical content of structure in the DCSs. Three transitions are studied, v i = 0, ji = 0, mi = 0 → vf = 3, jf = 0, 1, 2, mf = 0 at a translational energy of 0.04088 eV, where v, j, m are the vibrational, rotational and helicity quantum numbers respectively for the initial and final states. The input to our analyses consists of accurate quantum scattering (S) matrix elements computed for the Fu-Xu-Zhang potential energy surface, as used by Wang et al. in a computational simulation of their experimental DCSs. We prove that the pronounced peak at forward angles observed in the experimental and simulated DCSs for all three transitions is a glory. At larger angles, it is demonstrated that the 000 → 300 and 000 → 310 DCSs both possess a broad farside rainbow, which is accompanied by diffraction oscillations. We confirm the conjecture of Wang et al. that these diffraction oscillations arise from nearside-farside (NF) interference. We find that the reaction is N dominant for all three transitions. The theoretical techniques used to analyze the angular scattering include uniform semiclassical theories of glory and of rainbow scattering. We also make the first application of a semiclassical formula that is uniform for both glory + rainbow scattering. In addition, structure in the DCSs is analyzed using NF theory and local angular momentum theory, in both cases with three resummations of the partial wave series for the scattering amplitude. We make the first explicit application of the Thiele rational interpolation formula to extract the position and residue of the leading Regge pole from a set of S matrix elements, thereby making contact with complex angular momentum theories of DCSs, which interpret the angular scattering in terms of Regge resonances. Our calculations complement the exit-valley vibrationally-adiabatic analysis of Wang et al. © the Owner Societies 2011.


Zheng H.,Zhejiang University of Technology | Hu D.,Zhejiang University of Technology | Zhang L.,CAS Dalian Institute of Chemical Physics | Ma C.,Zhejiang University of Technology | Rufford T.,University of Western Australia
Minerals Engineering | Year: 2012

Thiol functionalized mesoporous silica (TFMS) with ordered hexagonal pore structure was fabricated by one-step synthesis pathway. The selective adsorption for precious metals was investigated using single component and binary adsorption solutions. The TFMS displayed strong affinity for gold or platinum in specific conditions with a large adsorption capacity, and showed a high selectivity in the binary solutions within 30 min. Furthermore, gold and platinum could be totally recovered by elution with 5 M HCl and 0.7 M thiourea-2 M HCl, respectively. © 2012 Elsevier Ltd. All rights reserved.


Wu H.-Y.,CAS Dalian Institute of Chemical Physics | Wu H.-Y.,Nanyang Technological University | Fan X.,Nanyang Technological University | Kuo J.-L.,Academia Sinica, Taiwan | Deng W.-Q.,CAS Dalian Institute of Chemical Physics
Journal of Physical Chemistry C | Year: 2011

The hydrogen spillover mechanism on B-doped graphene was explicitly investigated by first-principles calculations. By the incorporation of boron into graphene, our theoretical investigation shows that B doping can substantially enhance the adsorption strength for both H atoms and the metal cluster on the substrate. The firmly bound catalytic metal on B-doped graphene can effectively dissociate H2 molecules into H atoms, and the H atom is more likely to migrate from the bridge site of the H-saturated metal to the supporting graphene sheet. Further investigation on the BC3 sheet gives sufficiently low activation barriers for both H migration and diffusion processes; thus, more H atoms are expected to adsorb on BC3 substrate via H spillover under ambient conditions compared with the undoped graphene case. Our result is in good agreement with recent experimental findings that microporous carbon has an enhanced hydrogen uptake via boron substitution, implying that B doping with spillover is an effective approach in the modification of graphitic surface for hydrogen storage applications. © 2011 American Chemical Society.


Qiao B.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | Lin J.,CAS Dalian Institute of Chemical Physics | Li L.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2011

Ferric hydroxide supported copper oxide (CuO/Fe(OH)x) catalysts were prepared with a simple co-precipitation method and used for selective oxidation of CO in H2-rich gas. The effect of calcination temperatures and Cu loadings on the activity as well as the durability of the catalyst was investigated. When the calcination temperature was 200°C and the Cu loading was ranging from 7.2 to 17.3wt%, the catalyst gave the best performance with total conversion of CO achievable in a wide temperature window from 110°C to 150°C. To reveal the reason for the high activity of the catalysts, a variety of characterization techniques were employed. The results of XRD and TG-DTA indicated that the catalysts were amorphous even after being calcined at 400°C, which gave rise to large surface areas. HRTEM and XPS examinations indicated that the surface copper species were Cu2O with particle size of smaller than 5nm. In situ DRIFT and FT-IR results showed that the reduction of Cu2+ in the composite occurred even below room temperature when exposed to CO. The significant reducibility might contribute to the high activity of the catalysts. © 2011 Elsevier B.V.


Sun Z.,CAS Dalian Institute of Chemical Physics | Sun Z.,Duke University | Zhang D.H.,CAS Dalian Institute of Chemical Physics | Alexander M.H.,University of Maryland University College
Journal of Chemical Physics | Year: 2010

We describe a time-dependent wavepacket based method for the calculation of the state-to-state cross sections for the Cl+ H2 reaction including all couplings arising from the nonzero spin and electronic orbital angular momenta of the Cl atom. Reactant-product decoupling allows us to use a physically correct basis in both the reactant and the product arrangements. Our calculated results agree well with the experimental results of Yang and co-workers. We also describe a model with two coupled potential energy surfaces, which includes the spin-orbit coupling, which is responsible for the largest non-Born-Oppenheimer effects in the Cl+ H2 reaction but neglects the off-diagonal electronically diabatic coupling and all Coriolis couplings due to the electronic spin and orbital angular momenta. The comparison of the results of the full six-state and two-state models with an electronically adiabatic (one-state) description reveals that the latter describes well the reaction out of the ground spin-orbit state, while the two-state model, which is computationally much faster than the full six-state model, describes well the reaction from both the ground and excited spin-orbit states. © 2010 American Institute of Physics.


Czako G.,Emory University | Shuai Q.,Academia Sinica, Taiwan | Shuai Q.,CAS Dalian Institute of Chemical Physics | Liu K.,Academia Sinica, Taiwan | Bowman J.M.,Emory University
Journal of Chemical Physics | Year: 2010

The effects of the reactant bending excitations in the F+CHD3 reaction are investigated by crossed molecular beam experiments and quasiclassical trajectory (QCT) calculations using a high-quality ab initio potential energy surface. The collision energy (Ec) dependence of the cross sections of the F+CHD3 (vb =0,1) reactions for the correlated product pairs HF (v′) + CD3 (v2 =0,1) and DF (v′) + CHD2 (v4 =0,1) is obtained. Both experiment and theory show that the bending excitation activates the reaction at low Ec and begins to inactivate at higher Ec. The experimental F+CHD3 (vb =1) excitation functions display surprising peak features, especially for the HF (v′ =3) + CD3 (v2 =0,1) channels, indicating reactive resonances (quantum effects), which cannot be captured by quasiclassical calculations. The reactant state-specific QCT calculations predict that the v5 (e) bending mode excitation is the most efficient to drive the reaction and the v6 (e) and v5 (e) modes enhance the DF and HF channels, respectively. © 2010 American Institute of Physics.


Zhou X.,Ewha Womans University | Zhou X.,Yanbian University | Lee S.,Ewha Womans University | Xu Z.,CAS Dalian Institute of Chemical Physics | Yoon J.,Ewha Womans University
Chemical Reviews | Year: 2015

The development of chemosensors has become an important research topic in supramolecular analytical chemistry, and as a result, it has attracted the continuous interest of academic researchers in chemistry and biology. The strategy of using pH indicators was first employed in the construction of fluorescent sensors for CO2. Another strategy was developed based on the chemical reaction between amine and CO2 in which CO2 is a weak electrophile that can react with an active basic amine to form corresponding carbamate salt and ammonium salt. On the basis of this chemical mechanism, a series of fluorescent sensors has been achieved to date. One approach is directly inserting an amine group into the conjugated fluorophore. Sessler and co-workers constructed two colorimetric- and fluorescence-based CO2 sensors based on N-fused compounds. Chang and colleagues developed the fluorescent sensor by using a commercial resorufin for sulfite detection. In this case, sulfite can selectively react with the carbonyl carbon of the levulinate and yield a tetrahedral intermediate. This corresponding intermediate can next undergo an intermolecular cyclization to release the free resorufin moiety, resulting in an up to 57-fold fluorescence enhancement with a detection limit of 49 μM in aqueous solution. Fluorescent sensors for NO containing o-phenylenediamine (OPD) moieties and fluorophores have been developed by Nagano?s group and shown to be highly effective for visualizing this gas in vitro and in vivo.


Li A.,University of New Mexico | Guo H.,University of New Mexico | Sun Z.,CAS Dalian Institute of Chemical Physics | Klos J.,University of Maryland University College | Alexander M.H.,University of Maryland University College
Physical Chemistry Chemical Physics | Year: 2013

The state-to-state reaction dynamics of the title reaction is investigated on the ground electronic state potential energy surface using two quantum dynamical methods. The results obtained using the Chebyshev real wave packet method are in excellent agreement with those obtained using the time-independent method, except at low translational energies. It is shown that this exothermic hydrogen abstraction reaction is direct, resulting in a strong back-scattered bias in the product angular distribution. The HF product is highly excited internally. Agreement with available experimental data is only qualitative. We discuss several possible causes of disagreement with experiment. This journal is © 2013 the Owner Societies.


Xu J.,CAS Dalian Institute of Chemical Physics | Xu J.,University of Chinese Academy of Sciences | Wang A.,CAS Dalian Institute of Chemical Physics | Wang X.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Nano Research | Year: 2011

Highly ordered mesoporous carbon-alumina nanocomposites (OMCA) have been synthesized for the first time by a multi-component co-assembly method followed by pyrolysis at high temperatures. In this synthesis, resol phenol-formaldehyde resin (PF resin) and alumina sol were respectively used as the carbon and alumina precursors and triblock copolymer Pluronic F127 as the template. N2-adsorption measurements, X-ray diffraction, and transmission electron microscopy revealed that, with an increase of the alumina content in the nanocomposite from 11 to 48 wt.%, the pore size increased from 2.9 to 5.0 nm while the ordered mesoporous structure was retained. Further increasing the alumina content to 53 wt.% resulted in wormhole-like structures, although the pore size distribution was still narrow. The nanocomposite walls are composed of continuous carbon and amorphous alumina, which allows the ordered mesostructure to be well preserved even after the removal of alumina by HF etching or the removal of carbon by calcination in air. The OMCA nanocomposites exhibited good thermostability below 1000 °C; at higher temperatures the ordered mesostructure partially collapsed, associated with a phase transformation from amorphous alumina into γ-Al2O3. OMCA-supported Pt catalysts exhibited excellent performance in the one-pot transformation of cellulose into hexitols thanks to the unique surface properties of the nanocomposite. © 2011 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.


Xu F.,Zhengzhou University of Light Industry | Wang C.,CAS Dalian Institute of Chemical Physics | Wang H.,CAS Dalian Institute of Chemical Physics | Li X.,CAS Dalian Institute of Chemical Physics | Wan B.,CAS Dalian Institute of Chemical Physics
Green Chemistry | Year: 2015

We describe a new route for the synthesis of pyridines via [2 + 2 + 2] cycloaddition of diynes and oximes catalyzed by Rh(NBD)2BF4/MeO-Biphep using ethanol as an alternative green reaction medium, affording the desired pyridine derivatives in yields of up to 93%. This environmentally friendly method meets the requirement for green chemistry by minimizing pollution from solvents and is tolerant of a range of functional groups. This journal is © The Royal Society of Chemistry 2015.


Huang C.,Northwest University, China | Zheng C.,Northwest University, China | Li Y.,Dalian University of Technology | Wang Y.,Northwest University, China | And 2 more authors.
Briefings in Bioinformatics | Year: 2013

Systems pharmacology is an emerging field that integrates systems biology and pharmacology to advance the process of drug discovery, development and the understanding of therapeutic mechanisms. The aim of the present work is to highlight the role that the systems pharmacology plays across the traditional herbal medicines discipline, which is exemplified by a case study of botanical drugs applied in the treatment of depression. First, based on critically examined pharmacology and clinical knowledge, we propose a large-scale statistical analysis to evaluate the efficiency of herbs used in traditional medicines. Second, we focus on the exploration of the active ingredients and targets by carrying out complex structure-, omics- and network-based systematic investigations. Third, specific informatics methods are developed to infer drug- disease connections, with purpose to understand how drugs work on the specific targets and pathways. Finally, we propose a new systems pharmacology method, which is further applied to an integrated platform (Herbal medicine Systems Pharmacology) of blended herbal medicine and omics data sets, allowing for the systematization of current and traditional knowledge of herbal medicines and, importantly, for the application of this emerging body of knowledge to the development of new drugs for complex human diseases. © The Author 2013.


Wu H.Y.,Nanyang Technological University | Fan X.F.,Nanyang Technological University | Kuo J.-L.,Nanyang Technological University | Kuo J.-L.,Academia Sinica, Taiwan | Deng W.-Q.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2010

By the incorporation of C atoms into (BN)12 fullerene, our theoretical investigation shows that carbon doped boron nitride cages (BNC) can achieve a high hydrogen storage amount of 7.43 wt%, and dehydrogenation of the corresponding BNC hydrides (BNCH) is thermodynamically favored for practical applications of hydrogen energy, making BNC competitive candidates for hydrogen storage materials. © The Royal Society of Chemistry 2010.


He T.,CAS Dalian Institute of Chemical Physics | Wu H.,U.S. National Institute of Standards and Technology | Wu H.,University of Maryland University College | Wu G.,CAS Dalian Institute of Chemical Physics | And 7 more authors.
Energy and Environmental Science | Year: 2012

A new class of hydrogen storage materials, borohydride hydrazinates, was successfully synthesized. In particular, the bidentate NH 2NH 2 coordinates with LiBH 4 in molar ratios of 1:1 and 1:2 giving rise to a monoclinic LiBH 4·NH 2NH 2 and orthorhombic LiBH 4·2NH 2NH 2, respectively. Around 13.0 wt% H 2 can be released from LiBH 4·NH 2NH 2 at 140 °C in the presence of Fe-B catalysts. © The Royal Society of Chemistry 2012.


Jun E.J.,Ewha Womans University | Xu Z.,CAS Dalian Institute of Chemical Physics | Lee M.,Ewha Womans University | Yoon J.,Ewha Womans University
Tetrahedron Letters | Year: 2013

A new ratiometric fluorescent probe for fluoride ions was developed which complexed fluoride by a tridentate receptor of boronic acid and imidazolium. In the current study, a tridentate receptor 1 with one ortho boronic acid and two imidazolium groups was designed. The boron center can co-operate with imidazolium to bind F-. The formation of B-F complex stabilizes the interaction between fluoride and imidazolium which induces a ratiometric fluorescence response. With the addition of F-, a strongly increased fluorescent emission centered at 370 nm appears at the expense of the fluorescent emission centered at 445 nm. © 2013 Elsevier Ltd.All rights reserved.


Hong S.,Ewha Womans University | Pfaff F.F.,Humboldt University of Berlin | Kwon E.,Ewha Womans University | Wang Y.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2014

High-valent cobalt-oxo intermediates are proposed as reactive intermediates in a number of cobalt-complexmediated oxidation reactions. Herein we report the spectroscopic capture of low-spin (S = 1/2) CoIV-oxo species in the presence of redox-inactive metal ions, such as Sc3+, Ce3+, Y3+, and Zn2+, and the investigation of their reactivity in C-H bond activation and sulfoxidation reactions. Theoretical calculations predict that the binding of Lewis acidic metal ions to the cobaltoxo core increases the electrophilicity of the oxygen atom, resulting in the redox tautomerism of a highly unstable [(TAML)CoIII(O.)]2- species to a more stable [(TAML)CoIV(O)(Mn+)] core. The present report supports the proposed role of the redox-inactive metal ions in facilitating the formation of high-valent metal-oxo cores as a necessary step for oxygen evolution in chemistry and biology. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA.


Yang Z.,CAS Dalian Institute of Chemical Physics | Yang Z.,CAS Zhengzhou Research Institute | Hu J.,CAS Zhengzhou Research Institute | Zhao M.,CAS Zhengzhou Research Institute
Carbohydrate Polymers | Year: 2011

Inulin-type oligosaccharides with different degree of polymerization (DP) were isolated from the traditional Chinese medicine: Morina officinalis by size-exclusion chromatography, and their purities were determined by HPLC-ELSD equipped with cyclodextrin-bond column. Through analysis, the purities of obtained inulin-type oligosaccharides were higher more than 98% by one-step process. The structures of inulin-type oligosaccharides were confirmed by a combination of NMR, MS as well as comparison with already existing NMR data. Using d-fructose and the isolated inulin-type oligosaccharides as standards, a determination method of monosaccharide and inulin-type oligosaccharides in Morinda officinalis was first developed and validated. The validated method was successfully applied to analyze monosaccharide and oligosaccharides in three types of roots of M. officinalis and provided a new basis of assessment on quality of M. officinalis. © 2010 Elsevier Ltd. All rights reserved.


Yin Z.,Tianjin Polytechnic University | Chi M.,Oak Ridge National Laboratory | Zhu Q.,China National Institute of Clean and Low Carbon Energy | Ma D.,CAS Beijing National Laboratory for Molecular | And 2 more authors.
Journal of Materials Chemistry A | Year: 2013

Monodispersed bimetallic PdAu nanoparticles with controlled composition are prepared by an emulsion-assisted synthetic strategy with ternary metal precursors in the surfactants of oleic acid and oleylamine. The PdAu nanoparticles are loaded on a carbon support, and their electrocatalytic activities are tested for methanol oxidation in alkaline media. The bimetallic PdAu nanoparticles show superior electrocatalytic activities for methanol oxidation compared with the pure Pd nanoparticles prepared by the same method. The most active Pd30Au70 nanoparticles, with significantly low Pd content, even show remarkably higher activities than the commercial Pt/C catalyst. Various characterization techniques such as TEM, XPS and UV-vis are applied to study the nature of the catalysts. It is concluded that the increased activity is dependant on the unique Pd-rich shell and Au-rich core structure of such bimetallic PdAu particles as well as the nature of the Pd species on the catalyst surface. © 2013 The Royal Society of Chemistry.


Zhang H.,CAS Dalian Institute of Chemical Physics | Xu Q.,CAS Dalian Institute of Chemical Physics | Zhao Z.,CAS Dalian Institute of Chemical Physics | Zhang J.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Solar Energy Materials and Solar Cells | Year: 2012

The application of phase change materials (PCMs) for solar thermal-energy storage has received considerable attention in recent years due to their high storage density. A series of microencapsulated PCMs (micro-PCMs) with good phase change behavior have been synthesized through in-situ polymerization and the applications of the obtained micro-PCMs in thermal regulation of gypsum boards are presented in this study. Scanning electron microscope images reveal that the micro-PCMs were dispersed homogeneously in the gypsum boards. Differential scanning calorimeter results show that all the gypsum boards with different weight percentages of the micro-PCMs possess good phase change behavior. The melting and freezing temperatures as well as the latent heat of the gypsum board with 50 wt% or 60 wt% micro-PCMs and 3 wt% glass fibers are quite suitable for the potential thermal energy storage of building applications. Thermal cycling tests indicate that the gypsum board with micro-PCMs maintains excellent thermal reliability after 60 melting-freezing cycles. Furthermore, the gypsum boards with micro-PCMs show a good thermal-regulated property. The temperature of the board incorporated with 60 wt% micro-PCMs can be kept in the rage of 22-27 °C for about 1735 s due to the phase change of the inside micro-PCMs. In addition, the thermal-regulated gypsum boards achieve good thermal stability, high thermal capacity and thermal conductivity, especially for the sample incorporated with 50 wt% micro-PCMs. From the above results, it can be concluded that the gypsum boards incorporated with 50 wt% micro-PCMs have a good potential for thermal energy storage purpose in buildings. © 2012 Elsevier B.V. All rights reserved.


Li L.,CAS Yantai Institute of Coastal Zone Research | Li L.,Qinghai Academy of Agriculture and Forestry Research | Wang Y.,CAS Yantai Institute of Coastal Zone Research | Du Y.,CAS Dalian Institute of Chemical Physics | Qin S.,CAS Yantai Institute of Coastal Zone Research
Biotechnology Letters | Year: 2013

The polysaccharides in Jerusalem artichoke (JA) carry a substantial amount of energy that can be partly accessed through bioconversion into storable fuels. We review the potential for converting inulin into a variety of high value-added biorefinery products, including biofuels and biochemicals, and consider the feasibility of regarding JA as a model species of an inulin-rich crop. We discuss feedstock pretreatment, microorganisms used during fermentation, biorefinery products derived from JA, and how to enhance the economic competitiveness of JA as an energy crop. © 2012 Springer Science+Business Media Dordrecht.


Liu X.,University of Cambridge | Xu Z.,CAS Dalian Institute of Chemical Physics | Cole J.M.,University of Cambridge | Cole J.M.,University of New Brunswick
Journal of Physical Chemistry C | Year: 2013

Understanding the molecular origins of the optoelectronic properties of fluorophores provides rational guidelines for chemists to synthesize better-performing dyes. Factors affecting the UV-vis absorption spectral shift, molar extinction coefficients, and Stokes shift of fluorophores are herein examined at the molecular level, via both (time-dependent) density functional theory-based calculations and the empirical harmonic-oscillator-stabilization- energy (HOSE) and bond-length-alternation (BLA) models. The importance of these factors is discussed using six coumarin dyes as exemplars. In particular, a special focus is devoted to the Stokes shift, a critical parameter in fluorophores. It is demonstrated that incorporating a "rotational" substituent in a fluorophore molecule with tailored steric hindrance effects and resonance effects leads to a substantial increase in the Stokes shift, not only in coumarins but also in other chemical dye families: boron-dipyrromethenes (BODIPYs), cyanines, and stilbenes. Structure-property relationships concerning the rotational substituent are discussed in detail with examples of several dye families. These findings lead to the proposal of molecular design criteria that enable one to tune the Stokes shift. Such criteria provide a foundation for the molecular engineering of fluorophores with improved optoelectronic properties. © 2013 American Chemical Society.


Wang Y.,CAS Dalian Institute of Chemical Physics | Janardanan D.,Hebrew University of Jerusalem | Usharani D.,Hebrew University of Jerusalem | Han K.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
ACS Catalysis | Year: 2013

Oxidative C-H bond activation is a transformation of fundamental and practical interest, particularly if it can be carried out with high regio- and enantioselectivity. With nonheme iron oxygenases as inspiration (e.g., the Rieske oxygenases), a family of biomimetic nonheme iron complexes has been found to catalyze hydrocarbon oxidations by H2O2 via a postulated FeV(O)(OH) oxidant. Of particular interest is the Fe(S,S-PDP) catalyst discovered by White that, in the presence of acetic acid as an additive, performs selective C-H bond activation, even in complex organic molecules. The corresponding FeV(O)(OAc) species has been suggested as the key oxidant. We have carried out DFT studies to assess the viability of such an oxidant and discovered an alternative formulation. Theory reveals that the barrier for the formation of the putative FeV(O)(OAc) oxidant is too high for it to be feasible. Instead, a much lower barrier is found for the formation of a [(S,S-PDP)FeIII(κ2-peracetate)] species. In the course of C-H activation, this complex undergoes O-O bond homolysis to become a transient [(S,S-PDP)FeIV(O)(AcO·)] species that performs the efficient hydroxylation of alkanes. Thus, the acetic acid additive alters completely the nature of the high-valent oxidant, which remains disguised in the cyclic structure. This new mechanism can rationalize the many experimental observations associated with the oxidant formed in the presence of acetic acid, including the S = 1/2 EPR signal associated with the oxidant. These results further underscore the rich multioxidant scenario found in the mechanistic landscape for nonheme iron catalysts. © 2013 American Chemical Society.


Oloo W.N.,University of Minnesota | Meier K.K.,Carnegie Mellon University | Wang Y.,CAS Dalian Institute of Chemical Physics | Shaik S.,Hebrew University of Jerusalem | And 2 more authors.
Nature Communications | Year: 2014

Synthetically useful hydrocarbon oxidations are catalysed by bio-inspired non-heme iron complexes using hydrogen peroxide as oxidant, and carboxylic acid addition enhances their selectivity and catalytic efficiency. Talsi has identified a low-intensity g=2.7 electron paramagnetic resonance signal in such catalytic systems and attributed it to an oxoiron(V)-carboxylate oxidant. Herein we report the use of FeII (TPA*) (TPA*=tris(3,5- dimethyl-4-methoxypyridyl-2-methyl)amine) to generate this intermediate in 50% yield, and have characterized it by ultraviolet-visible, resonance Raman, Mössbauer and electrospray ionization mass spectrometric methods as a low-spin acylperoxoiron(III) species. Kinetic studies show that this intermediate is not itself the oxidant but decays via a unimolecular rate-determining step to unmask a powerful oxidant. The latter is shown by density functional theory calculations to be an oxoiron(V) species that oxidises substrate without a barrier. This study provides a mechanistic scenario for understanding catalyst reactivity and selectivity as well as a basis for improving catalyst design. © 2014 Macmillan Publishers Limited. All rights reserved.


Ma J.,CAS Dalian Institute of Chemical Physics | Ma J.,Johns Hopkins University | Zhang L.,CAS Dalian Institute of Chemical Physics | Liang Z.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
TrAC - Trends in Analytical Chemistry | Year: 2011

Fast, efficient characterization of proteins is becoming one of the hottest topics in the bioanalytical community, especially for large-scale proteomic studies. As an attractive approach, protein digestion by enzymes supported on various matrices (referred to as immobilized enzyme reactors, IMERs) has recently attracted much attention. In this article, we present a critical overview of some highly efficient IMERs and related analytical systems. We give major coverage to applications of IMERs in proteomic analysis, including protein-expression profiling, characterization of proteins with post-translational modifications, and protein quantification. We also comment on promising trends for IMERs in proteomics. © 2011 Elsevier Ltd.


Yang M.,CAS Dalian Institute of Chemical Physics | Zhang X.,California Institute of Technology | Han K.,CAS Dalian Institute of Chemical Physics
Proteins: Structure, Function and Bioinformatics | Year: 2010

Signal recognition particle (SRP) and its receptor (SR) play essential role in the SRP-dependent protein targeting pathway. They interact with one another to precisely regulate the targeting reaction. The mechanism of this interaction consists of at least two discrete conformational states: complex formation and GTPase activation. Although structural studies have provided valuable insights into the understanding of the SRP-SR interaction, it still remains unclear that how SRP and SR GTPases use their intrinsic conformational flexibilities to exert multiple allosteric regulations on this interaction process. Here, we use computational simulations to present the dynamic behavior of the SRP GTPases at an atomic level to gain further understanding of SRP-SR interaction. We show that: (i) equilibrium conformational fluctuations contain a cooperative inter-and intradomain structural rearrangements that are functionally relevant to complex formation, (ii) a series of residues in different domains are identified to correlate with each other during conformational rearrangements, and (iii) α3 and a4 helices at domain interface actively rearrange their relative conformation to function as a bridge between the N domain and the core region of the G domain. These results, in addition to structural studies, would harness our understanding of the molecular mechanism for SRP and SR interaction. © 2010 Wiley-Liss, Inc.


Ji N.,CAS Dalian Institute of Chemical Physics | Zheng M.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | Zhang T.,CAS Dalian Institute of Chemical Physics | Chen J.G.,University of Delaware
ChemSusChem | Year: 2012

A series of Ni-promoted W2C catalysts was prepared by means of a post-impregnation method and evaluated for the catalytic conversion of cellulose into ethylene glycol (EG). Quite different from our previously reported Ni-W2C/AC catalysts, which were prepared by using the co-impregnation method, the introduction of Ni by the post-impregnation method did not cause catalyst sintering, but resulted in redispersion of the W component, which was identified and characterized by means of XRD, TEM, and CO chemisorption. The highly dispersed Ni-promoted W2C catalyst was very active and selective in cellulose conversion into EG, with a 100% conversion of cellulose and a 73.0% yield in EG. The underlying reason for the enhanced catalytic performance was most probably the significantly higher dispersion of active sites on the catalyst. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang X.,Henan Normal University | Liu Y.,Henan Normal University | Wang Y.,CAS Dalian Institute of Chemical Physics
Theoretical Chemistry Accounts | Year: 2014

The conversion of cholesterol to pregnenolone is a physiologically essential process which initiates with two sequential hydroxylation processes catalyzed by cytochrome P450 side-chain cleavage enzyme (P450SCC). Extensive efforts have been exerted; however, the mechanistic details remain obscure. In this work, we employed the dispersion-corrected density functional theoretical (DFT-D) calculations to investigate the mechanistic details of such hydroxylation processes. Calculated results reveal that the active intermediate Compound I (CpdI) of P450SCC hydroxylates cholesterol efficiently, which coincides with previous spectrometric observations. The hydrogen bond effect of water molecule within the active site lowers the energy barrier significantly. Intriguingly, the adjacent hydrogen bond (H-bond) between the hydroxyl group of the substrate and the oxo group of CpdI in the second hydroxylation affects the H-abstraction significantly. Such H-bond was weakened during the C-H bond activation process, increasing the energy barriers by approximately 2 kcal/mol, which is different to the intermolecular H-bond effect of water903 found by Shaik et al. that decreases the barrier by about 4 kcal/mol. Such adjacent H-bond also affects the transition state by bending the alignment of the C-H-O moiety, and consequently lowering the kinetic isotope effect values. Besides, a series of DFT-D calculations (Grimme's D2, D3-zero, and D3-BJ methods) were performed and accessed to find out an appropriate protocol for H-bond containing hydroxylation process. Our results show that DFT-D single-point energies (SPE) based on geometries optimized with non-dispersion-corrected DFT varies drastically and sometime presents unreasonable results. DFT-D SPE calculations on DFT-D optimized geometries present stable and reasonable results. © Springer-Verlag Berlin Heidelberg 2014.


Zhou M.,Dalian Medical University | Ma H.,CAS Dalian Institute of Chemical Physics | Ma H.,Dalian Medical University | Lin H.,Dalian Medical University | Qin J.,CAS Dalian Institute of Chemical Physics
Biomaterials | Year: 2014

In proteinuric nephropathy, epithelial-to-mesenchymal transition (EMT) is an important mechanism that causes renal interstitial fibrosis. The precise role of EMT in the pathogenesis of fibrosis remains controversial, partly due to the absence of suitable invitro or invivo models. We developed two microfluidic and compartmental chips that reproduced the fluidic and three-dimensional microenvironment of proximal tubular epithelial cells invivo. Using one microfluidic device, we stimulated epithelial cells with a flow of healthy human serum, heat-inactivated serum and complement C3a, which mimicked the flow of urine within the proximal tubule. We observed that epithelial cells exposed to serum proteins became apoptotic or developed a mesenchymal phenotype. Incubating cells with C3a induced similar features. However, cells exposed to heat-inactivated serum did not adopt the mesenchymal phenotype. Furthermore, we successfully recorded the cellular morphological changes and the process of transmigration into basement membrane extract during EMT in real-time using another three-dimensional microdevice. In conclusion, we have established a cell-culture system that mimics the native microenvironment of the proximal tubule to a certain extent. Our data indicates that EMT did occur in epithelial cells that were exposed to serum proteins, and C3a plays an essential role in this pathological process. © 2013 Elsevier Ltd.


Wang M.,Beijing Institute of Technology | Liu X.,CAS Dalian Institute of Chemical Physics | Cao C.,Beijing Institute of Technology | Wang L.,Beijing Institute of Technology
Journal of Materials Chemistry | Year: 2012

Monodisperse CuInS 2-ZnS nanocrystals were synthesized in organic solvents and effectively transferred to aqueous phase with the aid of trimethyl(tetradecyl)ammonium bromide (TTAB). TTAB-stabilized CuInS 2-ZnS (CIS-ZnS-TTAB) nanocomposites exhibited good aqueous stability and preserved the high luminescence of the nanocrystals after phase transfer. More intriguingly, without any further modification, CIS-ZnS-TTAB showed a striking nuclear homing property, preferentially accumulating in the nuclei of living cells. This novel probe CIS-ZnS-TTAB may have applications in nuclear selective imaging and as a multifunctional drug carrier for nuclear targeted drug delivery. Our work provides a simple but effective way for hydrophobic nanomaterials to achieve both phase transfer and nuclear selectivity simultaneously. © 2012 The Royal Society of Chemistry.


Wang M.,Beijing Institute of Technology | Liu X.,CAS Dalian Institute of Chemical Physics | Cao C.,Beijing Institute of Technology | Shi C.,Beijing Institute of Technology
RSC Advances | Year: 2012

Cu-In-S ternary nanocrystals (NCs), with an average size of less than 10 nm, were synthesized in an aqueous solution containing bovine serum albumin (BSA). X-Ray powder diffraction (XRD) and selected-area electron diffraction (SAED) analyses showed that these NCs featured a roquesite structure. The composition of the NCs could be adjusted by controlling the molar ratio of the starting Cu/In precursors in the reaction solution, which led to a tunable band gap ranging from 1.48 eV to 2.30 eV. Cytotoxicity testing showed that the BSA-stabilized Cu-In-S NCs had little effect on the cell viability, which suggested that they are user-friendly and environmentally benign. With low cost, minimal energy input and environmental impact, this simple approach shows great potential for industrial applications. © 2012 The Royal Society of Chemistry.


Li W.,Michigan Technological University | Xin Q.,CAS Dalian Institute of Chemical Physics | Yan Y.,Center for Environmental Research and Technology
International Journal of Hydrogen Energy | Year: 2010

A series of carbon supported Pt-Fe bimetallic nanocatalysts (Pt-Fe/C) with varying Pt:Fe ratio were prepared by a modified ethylene glycol (EG) method, and then heat-treated under H2-Ar (10 vol%-H2) atmosphere at 900 °C. The Pt-Fe/C catalysts were characterized by X-ray diffraction (XRD), transmission electron spectroscopy (TEM), energy dispersive analysis by X-rays (EDX) and induced coupled plasma-atomic emission spectroscopy (ICP-AES). XRD analysis shows that Pt-Fe/C catalysts have small crystalline particles and form better Pt-Fe alloy structure with Fe amount increasing. TEM images evidence that small Pt-Fe nanoparticles homogeneously deposited on carbon support and addition of Fe can effectively prevent Pt particles agglomeration. EDX and ICP-AES show that Fe precursor cannot be fully reduced and deposited on carbon support through the adopted EG reduction approach. The electrochemical surface area of Pt-Fe/C catalyst obtained through hydrogen desorption areas in the CV curve increases with Fe atomic percentage increasing from 0 to ca. 50%, and then decreases with more Fe in the Pt-Fe/C catalyst. RDE tests show that the Pt-Fe/C with a Pt:Fe ratio of 1.2:1 and an optimized lattice parameter of around 3.894 Å has the highest mass activity and specific activity to oxygen reduction reaction (ORR). As cathode catalyst, this Pt-Fe/C (Pt:Fe ratio of 1.2:1) exhibits higher direct methanol fuel cell performance at 90 °C than Pt/C and other Pt-Fe/C catalysts, this could be attributed to its smaller particle size and better Pt-Fe alloy structure. © 2010 Professor T. Nejat Veziroglu.


Yu L.,CAS Dalian Institute of Chemical Physics | Pan X.,CAS Dalian Institute of Chemical Physics | Cao X.,Queen's University of Belfast | Hu P.,Queen's University of Belfast | Bao X.,CAS Dalian Institute of Chemical Physics
Journal of Catalysis | Year: 2011

Nitrogen-doped graphene (N-graphene) was reported to exhibit a good activity experimentally as an electrocatalyst of oxygen reduction reaction (ORR) on the cathode of fuel cells under the condition of electropotential of ∼0.04 V (vs. NHE) and pH of 14. This material is promising to replace or partially replace the conventionally used Pt. In order to understand the experimental results, ORR catalyzed by N-graphene is studied using density functional theory (DFT) calculations under experimental conditions taking the solvent, surface adsorbates, and coverages into consideration. Two mechanisms, i.e., dissociative and associative mechanisms, over different N-doping configurations are investigated. The results show that N-graphene surface is covered by O with 1/6 monolayer, which is used for reactions in this work. The transition state of each elementary step was identified using four different approaches, which give rise to a similar chemistry. A full energy profile including all the reaction barriers shows that the associative mechanism is more energetically favored than the dissociative one and the removal of O species from the surface is the rate-determining step. © 2011 Elsevier Inc. All rights reserved.


Zhong W.,Dalian Medical University | Zhang W.,Dalian Medical University | Wang S.,Dalian Medical University | Qin J.,CAS Dalian Institute of Chemical Physics
PLoS ONE | Year: 2013

In native fibrocartilage, mechanotransduction allows the cells to perceive the physical microenvironment not only through topographical cues from the extracellular matrix, but also through mechanical cues, such as interstitial flow. To create a microenvironment that simultaneously integrates nanotopography and flow stimulus, we developed a biomimetic microfluidic device embedded with aligned nanofibers to contain microchambers of different angles, which enabled the flow direction to form different angles with the fibers. Using this device, we investigated the effects of microfluidic and nanotopographical environment on the morphology and fibrochondrogenesis of mesenchymal stem cells (MSCs) and the involvement of RhoA/ROCK pathway and Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). The results showed that the flow direction perpendicular to aligned nanofibers was conducive to fibrochondrogenesis of MSCs. In addition, ROCK inhibitor and knockdown of YAP/TAZ disrupted fibrochondrogenic differentiation of MSCs. In conclusion, our data suggest the crucial role of mechanotransduction in regulating fibrochondrogenic differentiation of MSCs, which may be mediated by RhoA/ROCK pathway and YAP/TAZ. © 2013 Zhong et al.


Gai Q.-Q.,Beijing Institute of Technology | Qu F.,Beijing Institute of Technology | Zhang T.,Beijing Institute of Technology | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Journal of Chromatography A | Year: 2011

Currently, small proteins imprinting are more reported since large proteins molecular imprinting faces challenge due to their bulk size and complex structure. In this work, bovine serum albumin (BSA) surface-imprinted magnetic polymer was successfully synthesized based on atomic transfer radical polymerization (ATRP) method in the presence of common monomer (N-isopropylacrylamide) with the assistant of basic functional monomer (N-[3-(dimethylamino)propyl]-methacrylamide), which provides a achievable attempt for imprinting larger target proteins based on the ATPR with the mild reaction conditions. The BSA-imprinted polymer exhibited higher adsorption capacity and selectivity to BSA over the non-imprinted polymer. Competitive adsorption tests indicated the BSA-imprinted polymer had better selective adsorption and recognition properties to BSA in the mixture. The obtained BSA-imprinted polymer was applied to bovine serum, which also showed selectivity to BSA. In addition, a conventional aqueous two-phase solution of PEG/sulphate was used as elution for adsorbed BSA, which was compared with common NaCl elution. © 2011 Elsevier B.V.


Liu T.,CAS Dalian Institute of Chemical Physics | Liu T.,Dalian Medical University | Lin B.,CAS Dalian Institute of Chemical Physics | Qin J.,CAS Dalian Institute of Chemical Physics
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2010

Carcinoma-associated fibroblasts (CAFs) are a key determinant in malignant progression of cancer and represent an important target for cancer therapies. In this work, we present a microfluidic-based 3D co-culture device to reconstruct an in vitro tumor microenvironment and firstly investigate the effect of CAFs on cancer cell invasion in 3D matrix. This device is composed of six co-culture units, which enable parallel co-culture assays to be run in the presence of 3D extracellular matrix. Salivary gland adenoid cystic carcinoma (ACC) cells and CAFs embedded in matrix were co-cultured without direct contact on the device. Communication between ACC cells and CAFs could be established via medium diffused in matrix. It was observed that CAFs promoted ACC cell invasion in 3D matrix in a spheroid fashion, indicating that CAFs play a critical role in cancer invasion. We further demonstrated the effect of MMP inhibitor as an agent against CAF-promoted cancer invasion. This co-culture device reproducibly reflected the in vivo growth and invasion pattern of ACC and recreated the stroma-regulated ACC invasion. Thus, it provides a suitable platform for elucidating the mechanism of CAF-regulated cancer invasion and discovering anti-invasion drugs in a well defined 3D environment. © 2010 The Royal Society of Chemistry.


Ren Y.,Henan University of Science and Technology | Yan M.,Henan University of Science and Technology | Wang J.,Henan University of Science and Technology | Wang J.,Henan Normal University | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Breaking point: An effective reductive cleavage of inert aryl C-O bonds with an inexpensive iron catalyst has been developed. During this process, the reduction of the arene rings was not observed. This catalytic system also enabled the selective cleavage of the β-O-4 linkage of lignin model compounds under an atmosphere of hydrogen, thus offering an opportunity for the depolymerization of lignin. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chen S.,Chongqing University of Technology | Wei Z.,Chongqing University of Technology | Qi X.,Chongqing University of Technology | Dong L.,Chongqing University of Technology | And 4 more authors.
Journal of the American Chemical Society | Year: 2012

We have designed and synthesized a polyaniline (PANI)-decorated Pt/C@PANI core-shell catalyst that shows enhanced catalyst activity and durability compared with nondecorated Pt/C. The experimental results demonstrate that the activity for the oxygen reduction reaction strongly depends on the thickness of the PANI shell and that the greatest enhancement in catalytic properties occurs at a thickness of 5 nm, followed by 2.5, 0, and 14 nm. Pt/C@PANI also demonstrates significantly improved stability compared with that of the unmodified Pt/C catalyst. The high activity and stability of the Pt/C@PANI catalyst is ascribed to its novel PANI-decorated core-shell structure, which induces both electron delocalization between the Pt d orbitals and the PANI π-conjugated ligand and electron transfer from Pt to PANI. The stable PANI shell also protects the carbon support from direct exposure to the corrosive environment. © 2012 American Chemical Society.


Zhang Q.,Dalian Medical University | Liu T.,Dalian Medical University | Qin J.,CAS Dalian Institute of Chemical Physics
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2012

Circulating tumor aggregates exhibit a high metastatic potential and could potentially serve as an important target for cancer therapies. In this study, we developed a microfluidic model that reconstitutes and is representative of the principal components of biological blood vessels, including vessel cavity, endothelium, and perivascular matrix containing chemokines. Using this model, the transendothelial invasion of tumor aggregates can be observed and recorded in realtime. In this study we analyzed the extravasation process of salivary gland adenoid cystic carcinoma (ACC) cell aggregates. ACC aggregates transmigrated across the endothelium under the stimulation of chemokine CXCL12. The endothelial integrity was irreversibly damaged at the site of transendothelial invasion. The transendothelial invasion of ACC aggregates was inhibited by AMD3100, but the adhesion of ACC aggregates to the endothelium was not affected by the CXCR4 antagonist. This model allows for detailed study of the attachment and transendothelial invasion of tumor aggregates; thus, it would be a useful tool for analysis of the underlying mechanisms of metastasis and for testing novel anti-metastasis agents. This journal is © The Royal Society of Chemistry 2012.


Li D.,CAS Dalian Institute of Chemical Physics | Li D.,University of Kentucky | Huang X.,University of Kentucky | Han K.,CAS Dalian Institute of Chemical Physics | Zhan C.-G.,University of Kentucky
Journal of the American Chemical Society | Year: 2011

A series of computational methods were used to study how cytochrome P450 2A6 (CYP2A6) interacts with (S)-(-)-nicotine, demonstrating that the dominant molecular species of (S)-(-)-nicotine in CYP2A6 active site exists in the free base state (with two conformations, SRt and SRc), despite the fact that the protonated state is dominant for the free ligand in solution. The computational results reveal that the dominant pathway of nicotine metabolism in CYP2A6 is through nicotine free base oxidation. Further, first-principles quantum mechanical/molecular mechanical free energy (QM/MM-FE) calculations were carried out to uncover the detailed reaction pathways for the CYP2A6-catalyzed nicotine 5′-hydroxylation reaction. In the determined CYP2A6-(S)-(-)-nicotine binding structures, the oxygen of Compound I (Cpd I) can abstract a hydrogen from either the trans-5′-or the cis-5′-position of (S)-(-)-nicotine. CYP2A6-catalyzed (S)-(-)-nicotine 5′-hydroxylation consists of two reaction steps, that is, the hydrogen transfer from the 5′-position of (S)-(-)-nicotine to the oxygen of Cpd I (the H-transfer step), followed by the recombination of the (S)-(-)-nicotine moiety with the iron-bound hydroxyl group to generate the 5′-hydroxynicotine product (the O-rebound step). The H-transfer step is rate-determining. The 5′-hydroxylation proceeds mainly with the stereoselective loss of the trans-5′-hydrogen, that is, the 5′-hydrogen trans to the pyridine ring. The calculated overall stereoselectivity of ∼97% favoring the trans-5′-hydroxylation is close to the observed stereoselectivity of 89-94%. This is the first time it has been demonstrated that a CYP substrate exists dominantly in one protonation state (cationic species) in solution, but uses its less-favorable protonation state (neutral free base) to perform the enzymatic reaction. © 2011 American Chemical Society.


Shen H.,CAS Dalian Institute of Chemical Physics | Li Y.,CAS Dalian Institute of Chemical Physics | Ren P.,University of Texas at Austin | Zhang D.,CAS Dalian Institute of Chemical Physics | Li G.,CAS Dalian Institute of Chemical Physics
Journal of Chemical Theory and Computation | Year: 2014

Gay-Berne anisotropic potential has been widely used to evaluate the nonbonded interactions between coarse-grained particles being described as elliptical rigid bodies. In this paper, we are presenting a coarse-grained model for twenty kinds of amino acids and proteins, based on the anisotropic Gay-Berne and point electric multipole (EMP) potentials. We demonstrate that the anisotropic coarse-grained model, namely GBEMP model, is able to reproduce many key features observed from experimental protein structures (Dunbrack Library), as well as from atomistic force field simulations (using AMOEBA, AMBER, and CHARMM force fields), while saving the computational cost by a factor of about 10-200 depending on specific cases and atomistic models. More importantly, unlike other coarse-grained approaches, our framework is based on the fundamental intermolecular forces with explicit treatment of electrostatic and repulsion-dispersion forces. As a result, the coarse-grained protein model presented an accurate description of nonbonded interactions (particularly electrostatic component) between hetero/homodimers (such as peptide-peptide, peptide-water). In addition, the encouraging performance of the model was reflected by the excellent correlation between GBEMP and AMOEBA models in the calculations of the dipole moment of peptides. In brief, the GBEMP model given here is general and transferable, suitable for simulating complex biomolecular systems. © 2014 American Chemical Society.


Qiao Y.,CAS Dalian Institute of Chemical Physics | Qiao Y.,University of Kentucky | Han K.,CAS Dalian Institute of Chemical Physics | Zhan C.-G.,University of Kentucky
Biochemistry | Year: 2013

The pharmacological function of heroin requires an activation process that transforms heroin into 6-monoacetylmorphine (6-MAM), which is the most active form. The primary enzyme responsible for this activation process in human plasma is butyrylcholinesterase (BChE). The detailed reaction pathway of the activation process via BChE-catalyzed hydrolysis has been explored computationally, for the first time, in this study via molecular dynamics simulation and first-principles quantum mechanical/molecular mechanical free energy calculations. It has been demonstrated that the whole reaction process includes acylation and deacylation stages. The acylation consists of two reaction steps, i.e., the nucleophilic attack on the carbonyl carbon of the 3-acetyl group of heroin by the hydroxyl oxygen of the Ser198 side chain and the dissociation of 6-MAM. The deacylation also consists of two reaction steps, i.e., the nucleophilic attack on the carbonyl carbon of the acyl-enzyme intermediate by a water molecule and the dissociation of the acetic acid from Ser198. The calculated free energy profile reveals that the second transition state (TS2) should be rate-determining. The structural analysis reveals that the oxyanion hole of BChE plays an important role in the stabilization of rate-determining TS2. The free energy barrier (15.9 ± 0.2 or 16.1 ± 0.2 kcal/mol) calculated for the rate-determining step is in good agreement with the experimentally derived activation free energy (∼16.2 kcal/mol), suggesting that the mechanistic insights obtained from this computational study are reliable. The obtained structural and mechanistic insights could be valuable for use in the future rational design of a novel therapeutic treatment of heroin abuse. © 2013 American Chemical Society.


Jin J.,CAS Lanzhou Institute of Chemical Physics | Jin J.,CAS Dalian Institute of Chemical Physics | Pan F.,CAS Lanzhou Institute of Chemical Physics | Jiang L.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
ACS Nano | Year: 2014

Two-dimensional materials based on ternary system of B, C and N are useful ranging from electric devices to catalysis. The bonding arrangement within these BCN nanosheets largely determines their electronic structure and thus chemical and (or) physical properties, yet it remains a challenge to manipulate their bond structures in a convenient and controlled manner. Recently, we developed a synthetic protocol for the synthesis of crumpled BCN nanosheets with tunable B and N bond structure using urea, boric acid and polyethylene glycol (PEG) as precursors. By carefully selecting the synthesis condition, we can tune the structure of BCN sheets from s-BCN with B and N bond together to h-BCN with B and N homogenously dispersed in BCN sheets. Detailed experiments suggest that the final bond structure of B and N in graphene depends on the preferentially doped N structure in BCN nanosheets. When N substituted the in-plane carbon atom with all its electrons configured into the π electron system of graphene, it facilitates the formation of h-BCN with B and N in separated state. On the contrary, when nitrogen substituted the edge-plane carbon with the nitrogen dopant surrounded with the lone electron pairs, it benefits for the formation of B-N structure. Specially, the compound riched with h-BCN shows excellent ORR performance in alkaline solution due to the synergistic effect between B and N, while s-BCN dominant BCN shows graphite-like activity for ORR, suggesting the intrinsic properties differences of BCN nanosheets with different dopants bond arrangement. © 2014 American Chemical Society.


Gai Q.,Beijing Institute of Technology | Qu F.,Beijing Institute of Technology | Zhang T.,Beijing Institute of Technology | Zhang Y.,CAS Dalian Institute of Chemical Physics
Talanta | Year: 2011

Both of the magnetic particle adsorption and aqueous two-phase extraction (ATPE) were simple, fast and low-cost method for protein separation. Selective proteins adsorption by carboxyl modified magnetic particles was investigated according to protein isoelectric point, solution pH and ionic strength. Aqueous two-phase system of PEG/sulphate exhibited selective separation and extraction for proteins before and after magnetic adsorption. The two combination ways, magnetic adsorption followed by ATPE and ATPE followed by magnetic adsorption, for the separation of proteins mixture of lysozyme, bovine serum albumin, trypsin, cytochrome C and myloglobin were discussed and compared. The way of magnetic adsorption followed by ATPE was also applied to human serum separation. © 2011 Elsevier B.V. All rights reserved.


Qiao Y.,CAS Dalian Institute of Chemical Physics | Qiao Y.,University of Kentucky | Han K.,CAS Dalian Institute of Chemical Physics | Zhan C.-G.,University of Kentucky
Organic and Biomolecular Chemistry | Year: 2014

As the most active metabolite of heroin, 6-monoacetylmorphine (6-MAM) can penetrate into the brain for the rapid onset of heroin effects. The primary enzymes responsible for the metabolism of 6-MAM to the less potent morphine in humans are acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The detailed reaction pathways for AChE- and BChE-catalyzed hydrolysis of 6-MAM to morphine have been explored, for the first time, in the present study by performing first-principles quantum mechanical/molecular mechanical free energy calculations. It has been demonstrated that the two enzymatic reaction processes follow similar catalytic reaction mechanisms, and the whole catalytic reaction pathway for each enzyme consists of four reaction steps. According to the calculated results, the second reaction step associated with the transition state TS2a/TS2b should be rate-determining for the AChE/BChE-catalyzed hydrolysis, and the free energy barrier calculated for the AChE-catalyzed hydrolysis (18.3 kcal mol-1) is 2.5 kcal mol -1 lower than that for the BChE-catalyzed hydrolysis (20.8 kcal mol-1). The free energy barriers calculated for the AChE- and BChE-catalyzed reactions are in good agreement with the experimentally derived activation free energies (17.5 and 20.7 kcal mol-1 for the AChE- and BChE-catalyzed reactions, respectively). Further structural analysis reveals that the aromatic residues Phe295 and Phe297 in the acyl pocket of AChE (corresponding to Leu286 and Val288 in BChE) contribute to the lower energy of TS2a relative to TS2b. The obtained structural and mechanistic insights could be valuable for use in future rational design of a novel therapeutic treatment of heroin abuse. This journal is © 2014 the Partner Organisations.


Li Y.,East China University of Science and Technology | Zhang F.,East China University of Science and Technology | Liang X.,East China University of Science and Technology | Liang X.,CAS Dalian Institute of Chemical Physics | Yediler A.,Helmholtz Center for Environmental Research
Chemosphere | Year: 2013

This study evaluates the degradation efficiency of enrofloxacin (ENR) by catalytic wet air oxidation (CWAO) and ozonation. Results obtained by CWAO experiments show that 99.5% degradation, 37.0% chemical oxidation demand (COD) removal and 51.0% total organic carbon (TOC) conversion were obtained when 100mol% FeCl3 and 25mol% NaNO2 at 150°C under 0.5MPa oxygen pressure after 120min are used. The degradation products are identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS), gas chromatography-mass spectrometry (GC-MS) and ion chromatography (IC). The oxidation end products, F-, NO3- and NH4+ were determined by IC. The BOD5/COD ratio as a measure of the biodegradability of the parent compound increased from 0.01 to 0.12 after 120min of reaction time, indicating an improved biodegradability of the parent compound. The inhibition of bioluminescence of the marine bacteria V. fischeri decreased from 43% to 12% demonstrating a loss in toxicity of ENR during CWAO. Ozonation of 0.2mM ENR was carried out with an ozone concentration of 7.3gm-3 at pH 7. ENR decomposition with a degradation rate of 87% was obtained corresponding to the reaction time. Moderate changes in COD (18%) and TOC (17%) removal has been observed. The bioluminescence inhibition increased from 8% to 50%, due to the generation of toxic degradation products during ozonation. In comparison to the widely use of well developed method of ozonation CWAO exhibits better performance in terms of COD, TOC removals and generates less toxic products. © 2012 Elsevier Ltd.


Chen X.-F.,CAS Dalian Institute of Chemical Physics | Liu J.-F.,CAS Dalian Institute of Chemical Physics | Meng Z.-H.,Beijing Institute of Technology | Han K.-L.,CAS Dalian Institute of Chemical Physics
Theoretical Chemistry Accounts | Year: 2010

Simple C-NO2 homolysis, 4,6-dinitroanthranil (DNAt) production by dehydration, and the nitro-nitrite rearrangement-homolysis for gas-phase TNT decomposition were recently studied by Cohen et al. (J Phys Chem A 111:11074, 2007), based on DFT calculations. Apart from those three pathways, other possible initiation processes were suggested in this study, i.e., CH3 removal, O elimination, H escape, OH removal, HONO elimination, and nitro oxidizing adjacent backbone carbon atom. The intermediate, 3,5-dinitro-2(or 4)-methyl phenoxy, is more favor to decompose into CO and 3,5-dinitro-2(or 4)-methyl-cyclopentadienyl than to loss NO following nitro-nitrite rearrangement. Below ~1,335 K, TNT condensing to DNAt by dehydration is kinetically the most favor process, and the formations of substituted phenoxy and following cyclopentadienyl include minor contribution. Above ~1,335 K, simple C-NO2 homolysis kinetically dominates TNT decomposition; while the secondary process changes from DNAt production to CH3 removal above ~2,112 K; DNAt condensed from TNT by dehydration yields to that by sequential losses of OH and H above ~1,481 K and to nitro-nitrite rearrangement-fragmentation above ~1,778 K; O elimination replaces DNAt production above ~2,491 K, playing the third role in TNT decomposition; H escaping directly from TNT thrives in higher temperature (above ~2,812 K), as the fourth largest process. The kinetic analysis indicates that CH3 removal, O elimination, and H escape paths are accessible at the suggested TNT detonation time (~100-200 fs), besides C-NO2 homolysis. HONO elimination and nitro oxidizing adjacent backbone carbon atom paths are negligible at all temperatures. The calculations also demonstrated that some important species observed by Rogers and Dacons et al. are thermodynamically the most favor products at all temperatures, possibly stemmed from the intermediates including 4,6-dinitro-2-nitroso-benzyl alcohol, 3,5-dinitroanline, 2,6-dinitroso-4-nitro-phenylaldehyde, 3,5-dinitro-1-nitrosobenzene, 3,5-dinitroso-1-nitrobenzene, and nitrobenzene. All transition states, intermediates, and products have been indentified, the structures, vibrational frequencies, and energies of them were verified at the uB3LYP/6-311++G(d,p) level. Our calculated energies have mean unsigned errors in barrier heights of 3. 4-4. 2 kcal/mol (Lynch and Truhlar in J Phys Chem A 105:2936, 2001), and frequencies have the recommended scaling factors for the B3-LYP/6-311+G(d,p) method (Andersson and Uvdal in J Phys Chem A 109:2937, 2005; Merrick et al. in J Phys Chem A 111:11683, 2007). All calculations corroborate highly with the previous experimental and theoretical results, clarifying some pertinent questions. © 2010 Springer-Verlag.


Elowe S.,Max Planck Institute of Biochemistry | Dulla K.,Max Planck Institute of Biochemistry | Uldschmid A.,Max Planck Institute of Biochemistry | Uldschmid A.,Viramed Biotech AG | And 4 more authors.
Journal of Cell Science | Year: 2010

The BubR1 checkpoint protein performs multiple functions in mitosis. We have carried out a functional analysis of conserved motifs of human BubR1 (also known as BUB1B) and demonstrate that spindle assembly checkpoint (SAC) and chromosome attachment functions can be uncoupled from each other. Mutation of five proline-directed serine phosphorylation sites, identified in vivo by mass spectrometry, essentially abolishes attachment of chromosomes to the spindle but has no effect on SAC functionality. By contrast, mutation of the two conserved KEN boxes required for SAC function does not impact chromosome congression. Interestingly, the contribution of the two KEN-box motifs is not equal. Cdc20 associates with the N-terminal but not C-terminal KEN box, and mutation of the N-terminal KEN motif results in more severe acceleration of mitotic timing. Moreover, the two KEN motifs are not sufficient for maximal binding of Cdc20 and APC/C, which also requires sequences in the BubR1 C-terminus. Finally, mutation of the GLEBS motif causes loss of Bub3 interaction and mislocalization of BubR1 from the kinetochore; concomitantly, BubR1 phosphorylation as well as SAC activity and chromosome congression are impaired, indicating that the GLEBS motif is strictly required for both major functions of human BubR1.


Gai Q.-Q.,Beijing Institute of Technology | Qu F.,Beijing Institute of Technology | Liu Z.-J.,Beijing Institute of Technology | Dai R.-J.,Beijing Institute of Technology | Zhang Y.-K.,CAS Dalian Institute of Chemical Physics
Journal of Chromatography A | Year: 2010

Molecular imprinting as a promising and facile separation technique has received much attention because of their high selectivity for target molecules. In this study, the superparamagnetic lysozyme surface-imprinted polymer was prepared by a novel fabricating protocol, the grafting of the imprinted polymer on magnetic particles in aqueous media was done by atom transfer radical polymerization (ATRP), and the properties of the imprinted polymer were characterized in detail. Its high selective adsorption and recognition to lysozyme demonstrated the separation ability of the magnetic imprinted material to template molecule, and it has been used for quick and direct separation of lysozyme from the mixture of standard proteins and real egg white samples under an external magnetic field. Furthermore, the elution of lysozyme from the imprinted material was achieved by PEG/sulphate aqueous two-phase system, which caused lysozyme not only desorption from the imprinted materials but also redistribution in the top and bottom phase of aqueous two-phase system. The aqueous two-phase system exhibited some of the extraction and enrichment effect to desorbed lysozyme. Our results showed that ATRP is a promising method for the protein molecularly imprinted polymer preparation. © 2010 Elsevier B.V.


Qu Z.,Dalian University of Technology | Bu Y.,Dalian University of Technology | Qin Y.,Dalian University of Technology | Wang Y.,Dalian University of Technology | Fu Q.,CAS Dalian Institute of Chemical Physics
Applied Catalysis B: Environmental | Year: 2013

The effects of Ag on Mn/SBA-15 catalysts have been investigated in the toluene catalytic oxidation. The reactivity of catalysts is related closely to the Ag/Mn molar ratio, and the sample with 1:3 of Ag/Mn molar ratio exhibits the highest reactivity for toluene oxidation, with a complete conversion at 260°C. Based on the characterization results, it is found that Ag enters into MnO2 phase, and the Ag1.8Mn8O16 mixed phase forms. Meanwhile Ag leads to parts of MnO2 being transformed into Mn2O3. The Ag/Mn molar ratio has a strong influence on the molar ratio of the surface Mn4+ to Mn3+ and surface adsorbed oxygen (Oads) to lattice oxygen (Olatt) through the interaction between silver and MnOx. The coexistence of MnO2, Mn2O3, Ag1.8Mn8O16, and the strong interactions between Ag and Mn species exhibit a good synergetic interaction, which promotes the reducibility of catalysts and the formation of abundant active lattice oxygen, thus increasing the catalytic activity of toluene oxidation. And the formation of intermediate benzaldehyde should be closely link with the lattice oxygen of the Mn based catalyst. © 2012 Elsevier B.V.


Li A.,Lanzhou University of Technology | Li A.,CAS Dalian Institute of Chemical Physics | Sun H.-X.,Lanzhou University of Technology | Tan D.-Z.,CAS Dalian Institute of Chemical Physics | And 7 more authors.
Energy and Environmental Science | Year: 2011

Superhydrophobic conjugated microporous polymers show good selectivity, fast adsorption kinetics, excellent recyclability and absorbencies for a wide range of organic solvents and oils, which make them the promising candidates for potential applications, including liquid-liquid separation, water treatment and so on. © 2011 The Royal Society of Chemistry.


Xu C.,CAS Dalian Institute of Chemical Physics | Xu C.,Dalian University of Technology | Yang W.,CAS Dalian Institute of Chemical Physics | Guo Q.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Journal of the American Chemical Society | Year: 2014

Photocatalysis of methanol (CH3OH) on anatase (A)-TiO 2(101) has been investigated using temperature programmed desorption (TPD) method with 266 nm light at low surface temperatures. Experimental results show that CH3OH adsorbs on the A-TiO2(101) surface predominantly in molecular form, with only a small amount of CH3OH in dissociated form. Photocatalytic products, formaldehyde (CH2O) and methyl formate (HCOOCH3), have been detected under 266 nm light irradiation. In addition to H2O formation, H2 product is also observed by TPD spectroscopy. Experimental results indicate that H 2 product is formed via thermal recombination of H-atoms on the BBO sites from photocatalysis of CH3OH on the A-TiO2(101) surface, and H2 production on the A-TiO2(101) surface is significantly more efficient than that on the rutile (R)-TiO2(110) surface. © 2013 American Chemical Society.


Wang J.,Dalian University of Technology | Lu A.-H.,Dalian University of Technology | Li M.,CAS Dalian Institute of Chemical Physics | Zhang W.,Dalian University of Technology | And 3 more authors.
ACS Nano | Year: 2013

Thin porous alumina sheets have been synthesized using a lysine-assisted hydrothermal approach resulting in an extraordinary catalyst support that can stabilize Au nanoparticles at annealing temperatures up to 900 C. Remarkably, the unique architecture of such an alumina with thin sheets (average thickness ∼15 nm and length 680 nm) and rough surface is beneficial to prevent gold nanoparticles from sintering. HRTEM observations clearly showed that the epitaxial growth between Au nanoparticles and alumina support was due to strong interfacial interactions, further explaining the high sinter-stability of the obtained Au/Al2O3 catalyst. Consequently, despite calcination at 700 C, the catalyst maintains its gold nanoparticles of size predominantly 2 ± 0.8 nm. Surprisingly, catalyst annealed at 900 C retained the highly dispersed small gold nanoparticles. It was also observed that a few gold particles (6-25 nm) were encapsulated by an alumina layer (thickness less than 1 nm) to minimize the surface energy, revealing a surface restructuring of the gold/support interface. As a typical and size-dependent reaction, CO oxidation is used to evaluate the performance of Au/Al 2O3 catalysts. The results obtained demonstrated Au/Al2O3 catalyst calcined at 700 C exhibited excellent activity with a complete CO conversion at ∼30 C (T100% = 30 C), and even after calcination at 900 C, the catalyst still achieved its T 50% at 158 C. In sharp contrast, Au catalyst prepared using conventional alumina support shows almost no activity under the same preparation and catalytic test conditions. © 2013 American Chemical Society.


Wang Y.-Q.,Nankai University | Wang Y.-Q.,Taiyuan University of Technology | Zhao T.,Nankai University | He X.-W.,Nankai University | And 3 more authors.
Biosensors and Bioelectronics | Year: 2014

Herein, we synthesized a novel core-satellite CdTe/Silica/Au NCs hybrid sphere by covalently linking the separately synthesized highly fluorescent bovine serum albumin (BSA) stabilized gold nanoclusters (Au at BSA NCs) to the surface of the amino functionalized CdTe at SiO2 spheres by using the EDC chemistry. Numerous "satellites" of Au NCs were linked on the surface of the CdTe at SiO2 by the way of amide bonding. The synthesized dual-emission hybrid spheres were further characterized by the transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), UV-vis absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy, photoluminescence (PL), etc. Finally, the CdTe/Silica/Au NCs hybrid spheres were developed as ratiometric fluorescence probe for the determination of Cu2+ with high sensitivity and selectivity. The fluorescence intensity ratio (F545nm/F655nm) of the probe against the concentration of Cu2+ showed a good linear relationship from 6.0×10-7molL-1 to 100.0×10-7molL-1. It showed an excellent reproducibility (0.67% relative standard deviation for 10 replicate measurements of Cu2+ at 40.0×10-7molL-1) and low detection limit (4.1×10-7molL-1). Furthermore, the ratiometric fluorescent probe was successfully applied in the determination of Cu2+ in vegetable samples with satisfactory results. © 2013 Elsevier B.V.


Wang Y.,Northwest University, China | Li Y.,Dalian University of Technology | Ma Z.,Northwest University, China | Yang W.,Northwest University, China | Ai C.,CAS Dalian Institute of Chemical Physics
PLoS Computational Biology | Year: 2010

MicroRNAs (miRNAs) are endogenously produced ~21-nt riboregulators that associate with Argonaute (Ago) proteins to direct mRNA cleavage or repress the translation of complementary RNAs. Capturing the molecular mechanisms of miRNA interacting with its target will not only reinforce the understanding of underlying RNA interference but also fuel the design of more effective small-interfering RNA strands. To address this, in the present work the RNA-bound (Ago-miRNA, Ago-miRNAtarget) and RNA-free Ago forms were analyzed by performing both molecular dynamics simulations and thermodynamic analysis. Based on the principal component analysis results of the simulation trajectories as well as the correlation analysis in fluctuations of residues, we discover that: 1) three important (PAZ, Mid and PIWI) domains exist in Argonaute which define the global dynamics of the protein; 2) the interdomain correlated movements are so crucial for the interaction of Ago-RNAs that they not only facilitate the relaxation of the interactions between residues surrounding the RNA binding channel but also induce certain conformational changes; and 3) it is just these conformational changes that expand the cavity of the active site and open putative pathways for both the substrate uptake and product release. In addition, by thermodynamic analysis we also discover that for both the guide RNA 5′-end recognition and the facilitated site-specific cleavage of the target, the presence of two metal ions (of Mg2+) plays a predominant role, and this conclusion is consistent with the observed enzyme catalytic cleavage activity in the ternary complex (Ago-miRNA-mRNA). Our results find that it is the set of arginine amino acids concentrated in the nucleotide-binding channel in Ago, instead of the conventionally-deemed seed base-paring, that makes greater contributions in stabilizing the binding of the nucleic acids to Ago. © 2010 Wang et al.


Li B.,CAS Dalian Institute of Chemical Physics | Li F.,Dalian University of Technology | Bai S.,CAS Dalian Institute of Chemical Physics | Wang Z.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Energy and Environmental Science | Year: 2012

Here, we report that the water oxidation activity can be significantly increased by confining ruthenium molecular catalysts, such as Ru II(bda)(pic)2, in the nanocage of SBA-16. The TOF of RuII(bda)(pic)2 confined in the nanocage increased from 1.2 to 8.7 s-1 by simply increasing the number of Ru II(bda)(pic)2 molecules from one to seven in each nanocage, which is direct evidence for the "cooperative activation" mechanism involved in a binuclear reaction pathway for water oxidation reactions. The TOF of RuII(bda)(pic)2 confined in the nanocage can be as high as two times that of the homogeneous Ru II(bda)(pic)2 due to the enhanced "cooperative activation" in the limited space of nanocages. Moreover, preliminary kinetic studies suggest that the stability of the molecular catalysts can be greatly improved after confinement in the nanocage. This strategy not only provides a new strategy for the preparation of highly efficient solid-hosted catalysts for water oxidation, but also gives direct evidence for the oxygen evolution mechanism. This journal is © The Royal Society of Chemistry 2012.


Chen X.,University of Missouri - Kansas City | Li C.,CAS Dalian Institute of Chemical Physics | Gratzel M.,Ecole Polytechnique Federale de Lausanne | Kostecki R.,Lawrence Berkeley National Laboratory | Mao S.S.,Lawrence Berkeley National Laboratory
Chemical Society Reviews | Year: 2012

Over the past decades, there have been many projections on the future depletion of the fossil fuel reserves on earth as well as the rapid increase in green-house gas emissions. There is clearly an urgent need for the development of renewable energy technologies. On a different frontier, growth and manipulation of materials on the nanometer scale have progressed at a fast pace. Selected recent and significant advances in the development of nanomaterials for renewable energy applications are reviewed here, and special emphases are given to the studies of solar-driven photocatalytic hydrogen production, electricity generation with dye-sensitized solar cells, solid-state hydrogen storage, and electric energy storage with lithium ion rechargeable batteries. This journal is © The Royal Society of Chemistry 2012.


Ye Z.-S.,CAS Dalian Institute of Chemical Physics | Shi L.,CAS Dalian Institute of Chemical Physics | Shi L.,Dalian University of Technology | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Synlett | Year: 2014

Recent advance on asymmetric hydrogenation of aromatic carbocyclic rings and thiophenes has been described with the chiral ruthenium catalyst. It represents a great breakthrough in the area of asymmetric hydrogenation as well as opens up a new pathway for the facile synthesis of valuable optically active carbocyclic rings and dihydro- and tetrahydrothiophenes. © Georg Thieme Verlag Stuttgart New York.


Zheng X.,CAS Dalian Institute of Chemical Physics | Guo J.,Dalian University of Technology | Shi Y.,Dalian University of Technology | Xiong F.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Chemical Communications | Year: 2013

Porous chalcogels CoMoS4 and NiMoS4 made by a facile solution reaction displayed good electrocatalytic activity in the redox reaction of the I-/I3 - shuttle. Dye-sensitized solar cells with these ternary compounds as counter electrodes (CEs) showed photovoltaic performance similar to the devices made with noble metal platinum CE (7.46%). © The Royal Society of Chemistry 2013.


Chen M.-W.,CAS Dalian Institute of Chemical Physics | Cao L.-L.,CAS Dalian Institute of Chemical Physics | Cao L.-L.,Hunan University | Ye Z.-S.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemical Communications | Year: 2013

A novel and efficient method for the generation of o-quinone methide intermediates was developed from the readily available 2-tosylalkylphenols under the mild basic conditions, and their reactions with sulfur ylides were investigated for the stereoselective synthesis of trans-2,3-dihydrobenzofurans. This journal is © The Royal Society of Chemistry 2013.


Wang L.,Shanxi University | Wen Y.,Shanxi University | Liu J.,Shanxi University | Zhou J.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2011

Four new di-substituted phenanthroline-based compounds a-d have been designed and prepared, and they have been shown to induce the formation of anti-parallel structure of human telomeric G-quadruplex DNA by CD spectra. FRET assay indicates that the melting temperature increases (ΔTm values) of G-quadruplex in buffer (pH 7.4) containing 100 mM NaCl are 31.6, 34.6, 17.8 and 32.6°C for the compounds (1.0 μM) a, b, c and d, respectively. Competitive FRET assay shows that the four compounds exhibit a high G-quadruplex DNA selectivity over duplex DNA. Three of the compounds are the potent telomerase inhibitors and HeLa cell proliferation inhibitors. © 2011 The Royal Society of Chemistry.


Duan Y.,CAS Dalian Institute of Chemical Physics | Li L.,Dalian University of Technology | Chen M.-W.,CAS Dalian Institute of Chemical Physics | Yu C.-B.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of the American Chemical Society | Year: 2014

An efficient palladium-catalyzed asymmetric hydrogenation of a variety of unprotected indoles has been developed that gives up to 98% ee using a strong Brønsted acid as the activator. This methodology was applied in the facile synthesis of biologically active products containing a chiral indoline skeleton. The mechanism of Pd-catalyzed asymmetric hydrogenation was investigated as well. Isotope-labeling reactions and ESI-HRMS proved that an iminium salt formed by protonation of the C=C bond of indoles was the significant intermediate in this reaction. The important proposed active catalytic Pd-H species was observed with 1H NMR spectroscopy. It was found that proton exchange between the Pd-H active species and solvent trifluoroethanol (TFE) did not occur, although this proton exchange had been previously observed between metal hydrides and alcoholic solvents. Density functional theory calculations were also carried out to give further insight into the mechanism of Pd-catalyzed asymmetric hydrogenation of indoles. This combination of experimental and theoretical studies suggests that Pd-catalyzed hydrogenation goes through a stepwise outer-sphere and ionic hydrogenation mechanism. The activation of hydrogen gas is a heterolytic process assisted by trifluoroacetate of Pd complex via a six-membered-ring transition state. The reaction proceeds well in polar solvent TFE owing to its ability to stabilize the ionic intermediates in the Pd-H generation step. The strong Brønsted acid activator can remarkably decrease the energy barrier for both Pd-H generation and hydrogenation. The high enantioselectivity arises from a hydrogen-bonding interaction between N-H of the iminium salt and oxygen of the coordinated trifluoroacetate in the eight-membered-ring transition state for hydride transfer, while the active chiral Pd complex is a typical bifunctional catalyst, effecting both the hydrogenation and hydrogen-bonding interaction between the iminium salt and the coordinated trifluoroacetate of Pd complex. Notably, the Pd-catalyzed asymmetric hydrogenation is relatively tolerant to oxygen, acid, and water. © 2014 American Chemical Society.


Tian W.,CAS Dalian Institute of Chemical Physics | Zhao C.,CAS Dalian Institute of Chemical Physics | Zhao C.,Dalian University of Technology | Leng J.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of the American Chemical Society | Year: 2015

Single-crystal CH3NH3PbX3 (X = I-, Cl-, Br-) perovskite nanowires (NWs) and nanoplates (NPs), which demonstrate ultracompact sizes and exceptional photophysical properties, offer promises for applications in nanoscale photonics and optoelectronics. However, traditional electronic and transient techniques are limited by the dimensions of the samples, and characterizations of the carrier behavior (diffusion coefficient, charge mobility and diffusion length) in these NWs and NPs are extremely difficult. Herein, we report the direct visualization of the carrier diffusion process in individual single-crystal CH3NH3PbI3 and CH3NH3PbBr3 NWs and NPs using time-resolved and photoluminescence-scanned imaging microscopy. We report the diffusion coefficient (charge motility), which varies significantly between different NWs and NPs, ranging from 1.59 to 2.41 cm2 s-1 (56.4 to 93.9 cm2 V-1 s-1) for CH3NH3PbI3 and 0.50 to 1.44 cm2 s-1 (19.4 to 56.1 cm2 V-1 s-1) for CH3NH3PbBr3 and find this variation is independent of the shape and size of the sample. The average diffusion length is 14.0 ± 5.1 μm for CH3NH3PbI3 and 6.0 ± 1.6 μm for CH3NH3PbBr3. These results provide information that is essential for the practical applications of the single-crystal perovskite NWs and NPs, and the imaging microscopy may also be applicable to other optoelectronic materials. © 2015 American Chemical Society.


Han F.,Dalian University of Technology | Li W.-C.,Dalian University of Technology | Li M.-R.,CAS Dalian Institute of Chemical Physics | Lu A.-H.,Dalian University of Technology
Journal of Materials Chemistry | Year: 2012

A tubular composite, including ultrafine SnO 2 particles encapsulated in ordered tubular mesoporous carbon with thin walls and high pore volume, is fabricated through the in situ hydrolysis method. It is observed that up to 80 wt% of SnO 2 particles with size between 4-5 nm are highly dispersed and homogeneously encapsulated in the mesopore channels and no bulky aggregates are visible. The tubular composite exhibits a considerably high reversible capacity of 978 mA h g -1 and a high initial efficiency of 71% at a current density of 200 mA g -1 between 0.005-3 V. Its reversible capacity even increases up to 1039 mA h g -1 after 100 cycles, which is much higher than the conventional theoretical capacity of SnO 2 (782 mA h g -1), meanwhile, it also displays fast discharge/charge kinetics at a high current density of 1500 mA g -1. The excellent electrochemical performance is ascribed to its unique mesostructure by recruiting tubular mesoporous carbon with thin carbon walls (∼2 nm) and high pore volume (2.16 cm 3 g -1). This tubular nanostructure provides confined nanospace for hosting immobilized ultrafine SnO 2 with high loading, compensates volume expansion of SnO 2, warrants efficient contact between nanoparticles and carbon matrix before and after Li + insertion. We believe this special structure model might be extended for the fabrication of other cathode and anode electrode materials, to achieve high performance LIBs. © 2012 The Royal Society of Chemistry.


Xu X.,Northwest University, China | Wang X.,Northwest University, China | Li Y.,Dalian University of Technology | Wang Y.,Northwest University, China | Yang L.,CAS Dalian Institute of Chemical Physics
Nucleic Acids Research | Year: 2012

Nano-scale particles have attracted a lot of attention for its potential use in medical studies, in particular for the diagnostic and therapeutic purposes. However, the toxicity and other side effects caused by the undesired interaction between nanoparticles and DNA/RNA are not clear. To address this problem, a model to evaluate the general rules governing how nanoparticles interact with DNA/RNA is demanded. Here by, use of an examination of 2254 native nucleotides with molecular dynamics simulation and thermodynamic analysis, we demonstrate how the DNA/RNA native structures are disrupted by the fullerene (C60) in a physiological condition. The nanoparticle was found to bind with the minor grooves of double-stranded DNA and trigger unwinding and disrupting of the DNA helix, which indicates C60 can potentially inhibit the DNA replication and induce potential side effects. In contrast to that of DNA, C60 only binds to the major grooves of RNA helix, which stabilizes the RNA structure or transforms the configuration from stretch to curl. This finding sheds new light on how C60 inhibits reverse transcription as HIV replicates. In addition, the binding of C60 stabilizes the structures of RNA riboswitch, indicating that C60 might regulate the gene expression. The binding energies of C60 with different genomic fragments varies in the range of -56 to -10 kcal mol-1, which further verifies the role of nanoparticle in DNA/RNA damage. Our findings reveal a general mode by which C60 causes DNA/RNA damage or other toxic effects at a systematic level, suggesting it should be cautious to handle these nanomaterials in various medical applications. © 2012 The Author(s).


Lv W.,CAS Dalian Institute of Chemical Physics | Chen M.,Dalian University of Technology | Wu R.,CAS Dalian Institute of Chemical Physics
Soft Matter | Year: 2013

Graphene nanopore based sensor devices have shown great potential for the detection of DNA. To understand the fundamental aspects of DNA translocation through a graphene nanopore, in this work, molecular dynamics (MD) simulations and potential of mean force (PMF) calculations were carried out to investigate the impact of the number of graphene layers of small nanopores (2-3 nm) on DNA translocation. It was observed that the ionic conductance was sensitive to the number of graphene layers of open-nanopores, and the probability of DNA translocation through graphene nanopores was related to the thickness of the graphene nanopores. MD simulations showed that DNA translocation time was most sensitive to the thickness of graphene nanopores of 2.4 nm aperture, and the observed free energy barrier of PMFs and the profile change revealed the increased retardation of DNA translocation through bilayer graphene nanopores as compared to that through monolayer graphene nanopores. This journal is © 2013 The Royal Society of Chemistry.


Li G.,TU Eindhoven | Li G.,CAS Dalian Institute of Chemical Physics | Pidko E.A.,TU Eindhoven | Van Santen R.A.,TU Eindhoven | And 2 more authors.
Journal of Physical Chemistry C | Year: 2013

The stability of oxygenated and hydroxylated iron complexes in Fe/ZSM-5 is studied by periodic DFT calculations. The reaction paths for the interconversion of various potential iron-containing complexes confined in the zeolite matrix are discussed. It is demonstrated that the distribution of mononuclear [FeO]+ species depends only slightly on the specific local zeolite environment. For all binuclear complexes considered, a notable preference for the location at the larger eight-membered ring γ site in the sinusoidal channel is observed. Nevertheless, the formation of the mononuclear species [FeO]+ in realistic systems is very unlikely. Irrespective of their location inside the zeolite matrix, such species show a strong tendency toward self-organization into binuclear oxygen-bridged [Fe(μ-O)2Fe] 2+ complexes. Using ab initio thermodynamic analysis of the stability of different Fe complexes in ZSM-5, it is demonstrated that two distinct extraframework cationic complexes can be present in the Fe/ZSM-5 catalyst, namely, [FeIII(μ-O)2FeIII]2+ and [FeII(μ-O)FeII]2+. The [Fe II(μ-O)FeII]2+ complexes containing bivalent iron centers are mainly present in the Fe/ZSM-5 catalyst activated at low oxygen chemical potential and H2O-free conditions, whereas the formation of its Fe3+-containing counterpart [FeIII(μ- O)2FeIII]2+ is favored upon the high-temperature calcination in an O2-rich environment. © 2012 American Chemical Society.


Fan W.,CAS Dalian Institute of Chemical Physics | Tan D.,CAS Dalian Institute of Chemical Physics | Tan D.,Dalian University of Technology | Deng W.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

The structural, electronic and optical features of two metal-free triphenylamine (TPA) organic dyes (namely C206 and C217) before and after binding to a TiO 2 anatase nanoparticle have been investigated in detail, as a model for the corresponding dye-sensitized solar cells (DSSCs). The combination of density functional tight-binding (DFTB), density functional theory (DFT), and time-dependent DFT (TDDFT) approaches are employed. To understand the effects of the linker part in the TPA organic dyes on the energy conversion efficiency of the DSSCs, C217 and C206, which share the same donor and anchor parts but different linker parts, are theoretically evaluated. Our results show that compared with C206 containing just one thienothiophene unit as the linker, for C217 the introduction of one electron-rich 3,4- ethylenedioxythiophene group to the linker part results in stronger couplings with the TiO 2 conduction band and more efficient electron transfer. This difference contributes to the higher efficiency of C217 in DSSCs experiments. This study is expected to assist the molecular design of new and more efficient TPA-based organic dyes for the optimization of the DSSCs. © 2011 the Owner Societies.


Cai B.,CAS Dalian Institute of Chemical Physics | Cai B.,Dalian University of Technology | Xing Y.,CAS Dalian Institute of Chemical Physics | Yang Z.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Energy and Environmental Science | Year: 2013

Solid state hybrid solar cells with hybrid organolead halide perovskites (CH3NH3PbBr3 and CH3NH 3PbI3) as light harvesters and p-type polymer poly[N-9-hepta-decanyl-2,7-carbazole-alt-3,6-bis(thiophen-5-yl)-2,5-dioctyl-2, 5-di-hydropyrrolo[3,4-]pyrrole-1,4-dione] (PCBTDPP) as a hole transporting material were studied. The CH3NH3PbBr3- sensitized hybrid devices display an outstanding open circuit voltage (V oc) of ∼1.15 V, and the CH3NH3PbI 3-based cells exhibit a power conversion efficiency (PCE) of ∼5.55% along with high stability. The present results show that PCBTDPP is superior to the model p-type polymer P3HT as a HTM in these hybrid solar cells to achieve remarkably high Voc and high PCE. The possible mechanisms have been suggested. © 2013 The Royal Society of Chemistry.


Gao J.,CAS Dalian Institute of Chemical Physics | Gao J.,Dalian University of Technology | Bai S.,CAS Dalian Institute of Chemical Physics | Gao Q.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemical Communications | Year: 2011

The example of syn-aldol reaction of cyclohexanone to aldehyde was demonstrated based on chiral diamine organocatalysts and it was realized either by increasing the molecular size of acid additives or by introducing a hydrogen-bond donor into acid additives. © 2011 The Royal Society of Chemistry.


Sun Z.,CAS Dalian Institute of Chemical Physics | Sun Z.,Duke University | Guo H.,University of New Mexico | Zhang D.H.,CAS Dalian Institute of Chemical Physics
Journal of Chemical Physics | Year: 2010

The S -matrix for a scattering system provides the most detailed information about the dynamics. In this work, we discuss the calculation of S -matrix elements for the A+BC→AB+C, AC+B type reaction. Two methods for extracting S -matrix elements from a single wave packet in reactant Jacobi coordinates are reviewed and compared. Both methods are capable of extracting the state-to-state attributes for both product channels from a single wave packet propagation. It is shown through the examples of H+HD, Cl+ H2, and H+HCl reactions that such reactant coordinate based methods are easy to implement, numerically efficient, and accurate. Additional efficiency can be gained by the use of a L -shaped grid with two-dimensional fast Fourier transform. © 2010 American Institute of Physics.


Hao G.-P.,Dalian University of Technology | Li W.-C.,Dalian University of Technology | Qian D.,Dalian University of Technology | Wang G.-H.,Dalian University of Technology | And 6 more authors.
Journal of the American Chemical Society | Year: 2011

Porous carbon monoliths with defined multilength scale pore structures, a nitrogen-containing framework, and high mechanical strength were synthesized through a self-assembly of poly(benzoxazine-co-resol) and a carbonization process. Importantly, this synthesis can be easily scaled up to prepare carbon monoliths with identical pore structures. By controlling the reaction conditions, porous carbon monoliths exhibit fully interconnected macroporosity and mesoporosity with cubic Im3m symmetry and can withstand a press pressure of up to 15.6 MPa. The use of amines in the synthesis results in a nitrogen-containing framework of the carbon monolith, as evidenced by the cross-polarization magic-angle-spinning NMR characterization. With such designed structures, the carbon monoliths show outstanding CO2 capture and separation capacities, high selectivity, and facile regeneration at room temperature. At 1 bar, the equilibrium capacities of the monoliths are in the range of 3.3 - 4.9 mmol g- 1 at 0 °C and of 2.6 - 3.3 mmol g - 1 at 25 °C, while the dynamic capacities are in the range of 2.7 - 4.1 wt % at 25 °C using 14% (v/v) CO2 in N2. The carbon monoliths exhibit high selectivity for the capture of CO2 over N2 from a CO2/N2 mixture, with a separation factor ranging from 13 to 28. Meanwhile, they undergo a facile CO2 release in an argon stream at 25 °C, indicating a good regeneration capacity. © 2011 American Chemical Society.


Guo Q.,CAS Dalian Institute of Chemical Physics | Xu C.,CAS Dalian Institute of Chemical Physics | Xu C.,Dalian University of Technology | Ren Z.,CAS Dalian Institute of Chemical Physics | And 7 more authors.
Journal of the American Chemical Society | Year: 2012

We have investigated the photocatalysis of partially deuterated methanol (CD 3OH) and H 2O on TiO 2(110) at 400 nm using a newly developed photocatalysis apparatus in combination with theoretical calculations. Photocatalyzed products, CD 2O on Ti 5c sites, and H and D atoms on bridge-bonded oxygen (BBO) sites from CD 3OH have been clearly detected, while no evidence of H 2O photocatalysis was found. The experimental results show that dissociation of CD 3OH on TiO 2(110) occurs in a stepwise manner in which the O-H dissociation proceeds first and is then followed by C-D dissociation. Theoretical calculations indicate that the high reverse barrier to C-D recombination and the facile desorption of CD 2O make photocatalytic methanol dissociation on TiO 2(110) proceed efficiently. Theoretical results also reveal that the reverse reactions, i.e, O-H recombination after H 2O photocatalytic dissociation on TiO 2(110), may occur easily, thus inhibiting efficient photocatalytic water splitting. © 2012 American Chemical Society.


Fan W.,CAS Dalian Institute of Chemical Physics | Tan D.,Dalian University of Technology | Deng W.-Q.,CAS Dalian Institute of Chemical Physics
ChemPhysChem | Year: 2012

A series of metal-free acene-modified triphenylamine dyes (benzene to pentacene, denoted as TPA-AC1 to TPA-AC5) are investigated as organic sensitizers for application in dye-sensitized solar cells (DSSCs). A combination of density functional theory (DFT), density functional tight-binding (DFTB), and time-dependent DFT (TDDFT) approaches is employed. The effects of acene units on the spectra and electrochemical properties of the acene-modified TPA organic dyes are demonstrated. The dye/(TiO 2) 46 anatase nanoparticle systems are also simulated to show the electronic structures at the interface. The results show that from TPA-AC1 to TPA-AC5 with increasing sizes of the acenes, the absorption and fluorescence spectra are systematically broadened and red-shifted, but the oscillator strength and electron injection properties are reduced. The molecular orbital contributions show increasing localization on the bridging acene units from TPA-AC1 to TPA-AC5. From the theoretical examination of some key parameters including free enthalpy related to the electron injection, light-harvesting efficiency, and the shift of semiconductor conduction band, TPA-AC3 with an anthracene moiety demonstrates a balance of the above crucial factors. TPA-AC3 is expected to be a promising dye with desirable energetic and spectroscopic parameters in the DSSC field, which is consistent with recent experimental work. This study is expected to deepen our understanding of TPA-based organic dyes and assist the molecular design of new metal-free dyes for the further optimization of DSSCs. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu T.,CAS Dalian Institute of Chemical Physics | Liu T.,Dalian University of Technology | Liu X.,University of Cambridge | Spring D.R.,University of Cambridge | And 3 more authors.
Scientific Reports | Year: 2014

Viscosity is a fundamental physical parameter that influences diffusion in biological processes. The distribution of intracellular viscosity is highly heterogeneous, and it is challenging to obtain a full map of cellular viscosity with detailed organelle information. In this work, we report 1 as the first fluorescent viscosity probe which is able to quantitatively map cellular viscosity with detailed organelle information based on the PET mechanism. This probe exhibited a significant ratiometric fluorescence intensity enhancement as solvent viscosity increases. The emission intensity increase was attributed to combined effects of the inhibition of PET due to restricted conformational access (favorable for FRET, but not for PET), and the decreased PET efficiency caused by viscosity-dependent twisted intramolecular charge transfer (TICT). A full map of subcellular viscosity was successfully constructed via fluorescent ratiometric detection and fluorescence lifetime imaging; it was found that lysosomal regions in a cell possess the highest viscosity, followed by mitochondrial regions. © 2014 Macmillan Publishers Limited. All rights reserved.


Yang S.,Dalian University of Technology | Wang X.,Dalian University of Technology | Chu W.,CAS Dalian Institute of Chemical Physics | Song Z.,Dalian University of Technology | Zhao S.,Dalian University of Technology
Applied Catalysis B: Environmental | Year: 2011

Catalytic performance of platinum supported on H-ferrierite (H-FER) in selective catalytic reduction of NO and NO 2 by hydrogen (H 2-SCR) was investigated. 87.9% of the NO x was reduced with 56% of selectivity to N 2 when a gas mixture of 910ppm NO, 90ppm NO 2, 5000ppm H 2, 10% O 2 in N 2 passed through a 0.5wt.%Pt/H-FER catalyst at 110°C and gas hourly space velocity (GHSV) of 36,000h -1. It was found that the NO x reduction sharply decreased at higher reaction temperature, accompanied by large amount of NO 2 formation. The NO x conversion was also drastically decreased by increasing the concentration of NO 2 while holding the total concentration of NO+NO 2 in the feed gas mixture. Based on in situ Fourier transform infrared spectroscopy investigation, it was proposed that NO 2 and nitrate species were not essential intermediates of H 2-SCR over the catalyst, while NO δ+ species on Pt was a possible species for efficient elimination of NO. © 2011 Elsevier B.V.


Yu F.,Dalian University of Technology | Li P.,CAS Dalian Institute of Chemical Physics | Song P.,CAS Dalian Institute of Chemical Physics | Wang B.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemical Communications | Year: 2012

We presented the design, synthesis, spectroscopy, and biological applications of DA-Cy, an on-off-on fluorescent probe to monitor H 2O 2 oxidative stress and thiols reducing repair in living cells and tissues simply and directly. © The Royal Society of Chemistry 2012.


Ji M.,Dalian University of Technology | Zhang X.,Dalian University of Technology | Wang J.,CAS Dalian Institute of Chemical Physics | Park S.-E.,Inha University
Journal of Molecular Catalysis A: Chemical | Year: 2013

Fe-doped MgAl2O4 spinel catalyst of MgFe 0.1Al1.9O4 and supported catalyst of Fe 2O3-MgO/γ-Al2O3 for ethylbenzene dehydrogenation in the presence of CO2 were studied by Mössbauer spectroscopy (MS) combining with the partial reduction method in the presence of H2, and the catalytic activity of the ferrous iron species was discussed. The results showed that the catalytic performance of Fe3+ existing in spinel is superior to α-Fe2O 3, and the synergistic effect between Fe2+ and Fe 3+ might indeed increase the catalytic activity since Fe 2+-O2- formed in the process of reduction has moderate basicity, which was more favorable for desorption of CO2 compared with Mg2+-O2-. The reduced MgFe0.1Al 1.9O4 containing Fe2+ of around 25% exhibits much higher catalytic activity than unreduced catalyst, with improved styrene yield nearly 2 times to 45.0%. MgxFe1-xO as another ferrous iron species formed in the reduction process of Fe2O 3-MgO/γ-Al2O3 showed inconspicuously catalytic activity. © 2013 Elsevier Ltd. All rights reserved.


Li J.,University of New Mexico | Chen J.,CAS Dalian Institute of Chemical Physics | Zhang D.H.,CAS Dalian Institute of Chemical Physics | Guo H.,University of New Mexico
Journal of Chemical Physics | Year: 2014

A permutationally invariant global potential energy surface for the HOCO system is reported by fitting a larger number of high-level ab initio points using the newly proposed permutation invariant polynomial-neural network method. The small fitting error (∼5 meV) indicates a faithful representation of the potential energy surface over a large configuration space. Full-dimensional quantum and quasi-classical trajectory studies of the title reaction were performed on this potential energy surface. While the results suggest that the differences between this and an earlier neural network fits are small, discrepancies with state-to-state experimental data remain significant. © 2014 AIP Publishing LLC.


Yu F.,CAS Dalian Institute of Chemical Physics | Yu F.,Dalian University of Technology | Song P.,CAS Dalian Institute of Chemical Physics | Li P.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Analyst | Year: 2012

We present the design, synthesis, spectroscopy, and biological applications of PyBor, a new type of fluorescent probe for peroxynitrite detection in aqueous solution and living cells. The probe employs pyrene as the fluorophore, and is equipped with a chemically responsive unit boronate. The fluorescent probe can selectively detect peroxynitrite with fluorimetric determination and high-performance liquid chromatography analyses in aqueous solution and RAW264.7 cells intracellular free extracts. We also study our probe to time dependent peroxynitrite release from 3-morpholinylsydnonimine hydrochloride. Confocal microscopy experiments using mouse macrophage cell line RAW264.7 show that PyBor is able to detect the different intracellular peroxynitrite levels. In addition, we have performed quantum chemical calculations with TD-DFT/M06/TZVP level with COSMO solvation model basis sets using a suite of Gaussian 09 programs to provide insights into the structure optical properties of PyBor and PyOH. © 2012 The Royal Society of Chemistry.


Zhang D.H.,CAS Dalian Institute of Chemical Physics | Guo H.,University of New Mexico
Annual Review of Physical Chemistry | Year: 2016

In this review, we survey the latest advances in theoretical understanding of bimolecular reaction dynamics in the past decade. The remarkable recent progress in this field has been driven by more accurate and efficient ab initio electronic structure theory, effective potential-energy surface fitting techniques, and novel quantum scattering algorithms. Quantum mechanical characterization of bimolecular reactions continues to uncover interesting dynamical phenomena in atom-diatom reactions and beyond, reaching an unprecedented level of sophistication. In tandem with experimental explorations, these theoretical developments have greatly advanced our understanding of key issues in reaction dynamics, such as microscopic reaction mechanisms, mode specificity, product energy disposal, influence of reactive resonances, and nonadiabatic effects. Copyright © 2016 by Annual Reviews. All rights reserved.


Zhao J.,CAS Dalian Institute of Chemical Physics | Zhao J.,Dalian University of Technology
Journal of Chemical Physics | Year: 2013

We investigated spin-orbit-induced intersystem crossing effects in the title reaction by the time-dependent wave-packet method combined with an extended split operator scheme. We performed non-adiabatic calculations of the fine-structure-resolved cross section and adiabatic calculations of integral cross section. The calculations are based on the potential energy surfaces of 3A' and the two degenerate 3A'' states [S. Rogers, D. Wang, A. Kuppermann, and S. Walch, J. Phys. Chem. A 104, 2308 (2000)]10.1021/jp992985g, together with the spin-orbit coupling matrix [B. Maiti and G. C. Schatz, J. Chem. Phys. 119, 12360 (2003)]10.1063/1.1623481 and singlet 1A' potential energy surface [J. Dobbyn and P. J. Knowles, Faraday Discuss. 110, 247 (1998)]. The results of the O(3P)+ D 2 are similar to those of the O(3P)+ H2 reaction. The product spin state-resolved reaction cross section and the total reaction cross section both show that the adiabatic channel is dominant in all cases, and the non-adiabatic channels have cross sections of several orders of magnitude smaller than the adiabatic channels at high collision energy. Although the cross sections caused by the intersystem crossing effects in the O( 3P) +D2 reaction are larger than those in the O( 3P)+2 reaction, the differences in non-adiabaticity between these two reaction systems are quite modest. Based on the results of the O(3P) +H2 reaction, we can predict that the influence of spin-orbit on the total reaction cross sections of the O(3P)+ D 2 reaction is also insignificant. However, these non-adiabatic effects can be reflected in the presence of some forward-scattering in the angular distribution for the OD product. © 2013 American Institute of Physics.


Liu T.,Dalian University of Technology | Liu T.,CAS Dalian Institute of Chemical Physics | Xu Z.,Dalian University of Technology | Xu Z.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Organic Letters | Year: 2013

In this work, a 1,8-naphthalimide-derived fluorescent probe for H 2S based on the thiolysis of dinitrophenyl ether is reported. This probe exhibits turn-on fluorescence detection of H2S in bovine serum and lysosome-targetable fluorescent imaging of H2S with excellent selectivity. © 2013 American Chemical Society.


Qi Z.,CAS Dalian Institute of Chemical Physics | Qi Z.,Dalian University of Technology | Wang M.,Dalian University of Technology | Li X.,CAS Dalian Institute of Chemical Physics
Organic Letters | Year: 2013

Under redox-neutral conditions, rhodium(III)-catalyzed C-H annulation of N-tert-butyl-α-arylnitrones with internal alkynes has been realized for the synthesis of indenones under mild conditions. This reaction proceeded in moderate to high yields and with good functional group tolerance. © 2013 American Chemical Society.


Li Y.,CAS Dalian Institute of Chemical Physics | Ruan Q.,Dalian University of Technology | Ye G.,CAS Dalian Institute of Chemical Physics | Lu X.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Journal of Chromatography A | Year: 2012

Non-targeted metabolic profiling is the most widely used method for metabolomics. In this paper, a novel approach was established to transform a non-targeted metabolic profiling method to a pseudo-targeted method using the retention time locking gas chromatography/mass spectrometry-selected ion monitoring (RTL-GC/MS-SIM). To achieve this transformation, an algorithm based on the automated mass spectral deconvolution and identification system (AMDIS), GC/MS raw data and a bi-Gaussian chromatographic peak model was developed. The established GC/MS-SIM method was compared with GC/MS-full scan (the total ion current and extracted ion current, TIC and EIC) methods, it was found that for a typical tobacco leaf extract, 93% components had their relative standard deviations (RSDs) of relative peak areas less than 20% by the SIM method, while 88% by the EIC method and 81% by the TIC method. 47.3% components had their linear correlation coefficient higher than 0.99, compared with 5.0% by the EIC and 6.2% by TIC methods. Multivariate analysis showed the pooled quality control samples clustered more tightly using the developed method than using GC/MS-full scan methods, indicating a better data quality. With the analysis of the variance of the tobacco samples from three different planting regions, 167 differential components (p< 0.05) were screened out using the RTL-GC/MS-SIM method, but 151 and 131 by the EIC and TIC methods, respectively. The results show that the developed method not only has a higher sensitivity, better linearity and data quality, but also does not need complicated peak alignment among different samples. It is especially suitable for the screening of differential components in the metabolic profiling investigation. © 2012 Elsevier B.V.


Yu F.,CAS Dalian Institute of Chemical Physics | Yu F.,Dalian University of Technology | Song P.,CAS Dalian Institute of Chemical Physics | Li P.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemical Communications | Year: 2012

We describe the synthesis, properties, and application of two reversible fluorescent probes, mCy-TemOH and Cy-TemOH, for HOBr sensing and imaging in live cells. The two probes contain a hydroxylamine functional group for the monitoring of HOBr oxidation/ascorbic acid reduction events. Confocal fluorescence microscopy has established the HOBr detection in live-cells. This journal is © 2012 The Royal Society of Chemistry.


Guo X.,CAS Dalian Institute of Chemical Physics | Fu Q.,CAS Dalian Institute of Chemical Physics | Ning Y.,CAS Dalian Institute of Chemical Physics | Wei M.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Journal of the American Chemical Society | Year: 2012

A noble metal (NM) can stabilize monolayer-dispersed surface oxide phases with metastable nature. The formed "oxide-on-metal" inverse catalyst presents better catalytic performance than the NM because of the introduction of coordinatively unsaturated cations at the oxide-metal boundaries. Here we demonstrate that an ultrathin NM layer grown on a non-NM core can impose the same constraint on the supported oxide as the bulk NM. Cu@Pt core-shell nanoparticles (NPs) decorated with FeO patches use much less Pt but exhibit performance similar to that of Pt NPs covered with surface FeO patches in the catalytic oxidation of CO. The "oxide-on-core@shell" inverse catalyst system may open a new avenue for the design of advanced nanocatalysts with decreased usage of noble metals. © 2012 American Chemical Society.


Wang F.,CAS Dalian Institute of Chemical Physics | Xu J.,CAS Dalian Institute of Chemical Physics | Dubois J.-L.,Arkema | Ueda W.,Hokkaido University
ChemSusChem | Year: 2010

An embedded catalyst for the oxidative dehydration of glycerol, featuring iron oxide (FeO x) domains on the surface of an iron orthovanadate (FeVO 4) phase, is developed. Catalytic reactions are conducted in a fixed-bed reactor at 300°C with a feed composition N 2/O 2/H 2O/glycerol=66.6:1.7:30.3:1.5. Catalytic results show that the catalyst exhibits a better performance than an FeO x catalyst prepared by impregnation and than a mixture of FeVO 4 and Fe 2O 3. The best yield for acrylic acid was 14%. The presence of FeO x domains on the surface of FeVO 4 catalyzes the oxidation of acrolein to acrylic acid. The catalysts are characterized by a range of techniques. The interaction between the nanometer-sized FeO x domains and the FeVO 4 phase is strong enough to stabilize the FeO x and retain its high activity. The proximity of the two phases provides an environment for the dehydration of glycerol and the oxidation of acrolein to acrylic acid. The rapid growth of the biodiesel industry has lead to the production of large amounts of glycerol, as the compound is a major byproduct of biodiesel production. A catalyst with nanometer-sized FeO x domains embedded in the surface of FeVO 4 phase is active for the oxidative dehydration of glycerol to acrolein and acrylic acid, turning the byproduct into valuable chemicals. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Gao S.,Dalian University of Technology | Wang X.,Dalian University of Technology | Chu W.,CAS Dalian Institute of Chemical Physics
Microporous and Mesoporous Materials | Year: 2012

Uniform SUZ-4 zeolite nanofiber (about 12 × 1500 nm) was obtained for the first time. The SUZ-4 zeolite was synthesized by hydrothermal treatment of the initial aluminosilicate gel at 150 °C with the assistance of definite amount of special seed slurry while without additional use of template. It was found that morphology of the SUZ-4 zeolite synthesized can be simply controlled by the character of seed slurry that is mainly determined by the crystallization period in preparation. The seed slurry containing plenty of less stable SUZ-4 crystallites obtained by crystallizing the aluminosilicate gel (7.9 KOH:1.0 Al 2O 3:2.6 TEAOH:21.2 SiO 2:498.6 H 2O) under rotation at 150 °C for 16 h leads to the synthesis of nanofibrous SUZ-4, while that primarily containing stable SUZ-4 crystallites obtained by prolonged crystallization period leads to the synthesis of rod-like zeolite. © 2012 Elsevier Inc. All rights reserved.


Shao T.,CAS Dalian Institute of Chemical Physics | Shao T.,Dalian University of Technology | Wen B.,Dalian University of Technology | Yang H.,CAS Dalian Institute of Chemical Physics | Yang H.,Shandong University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

In the present work, laser-parameter effects on the isolated attosecond pulse generation from two-color high-order harmonic generation (HHG) process are theoretically investigated by use of a wave-packet dynamics method. A 6-fs, 800-nm, 6×1014W⊃/cm2, linearly polarized laser pulse serves as the fundamental driving pulse and parallel linearly polarized control pulses at 400 nm (second harmonic) and 1600 nm (half harmonic) are superimposed to create a two-color field. Of the two techniques, we demonstrate that using a half-harmonic control pulse with a large relative strength and zero phase shift relative to the fundamental pulse is a more promising way to generate the shortest attosecond pulses. As a consequence, an isolated 12-as pulse is obtained by Fourier transforming an ultrabroad xuv continuum of 300 eV in the HHG spectrum under half-harmonic control scheme when the relative strength √R=0.6 and relative phase =0. © 2010 The American Physical Society.


Shi L.,CAS Dalian Institute of Chemical Physics | Shi L.,Dalian University of Technology | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics | Zhou Y.-G.,Dalian University of Technology
ChemCatChem | Year: 2015

Frustration is key: Enantioselective hydrogenation under metal-free conditions by using frustrated Lewis pair (FLP) catalysts is a significant breakthrough for catalytic hydrogenation, which is dominated by chiral transition-metal catalysts. This success demonstrates the potential of FLP chemistry for the synthesis of valuable chiral compounds by means of metal-free catalytic hydrogenation. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.


Qu Z.,Dalian University of Technology | Miao L.,Dalian University of Technology | Wang H.,Dalian University of Technology | Fu Q.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2015

Highly dispersed Fe2O3 nanoparticles supported on carbon nanotubes, prepared by a simple ethanol-assisted impregnation method, showed above 90% NO conversion and selectivity at low temperatures (200-325 °C). Moreover excellent durability and stability towards SO2/H2O was obtained. This journal is © The Royal Society of Chemistry 2015.


Wang L.,Dalian University of Technology | Xiao Y.,Dalian University of Technology | Tian W.,CAS Dalian Institute of Chemical Physics | Deng L.,CAS Dalian Institute of Chemical Physics
Journal of the American Chemical Society | Year: 2013

We have developed Lyso-V, the first fluorescent probe of lysosomal viscosity. Because of its lysosome-actived fluorescence characteristics, Lyso-V has proved to be an ideal lysosomal tracer with high spatial and temporal resolution under laser confocal microscopy. More importantly, Lyso-V shows its practical applicability in real-time quantification of lysosomal viscosity changes in live cells through fluorescence lifetime imaging microscopy. © 2013 American Chemical Society.


Mu R.,CAS Dalian Institute of Chemical Physics | Fu Q.,CAS Dalian Institute of Chemical Physics | Xu H.,CAS Dalian Institute of Chemical Physics | Zhang H.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
Journal of the American Chemical Society | Year: 2011

Various well-defined Ni-Pt(111) model catalysts are constructed at atomic-level precision under ultra-high-vacuum conditions and characterized by X-ray photoelectron spectroscopy and scanning tunneling microscopy. Subsequent studies of CO oxidation over the surfaces show that a sandwich surface (NiO 1-x/Pt/Ni/Pt(111)) consisting of both surface Ni oxide nanoislands and subsurface Ni atoms at a Pt(111) surface presents the highest reactivity. A similar sandwich structure has been obtained in supported Pt-Ni nanoparticles via activation in H2 at an intermediate temperature and established by techniques including acid leaching, inductively coupled plasma, and X-ray adsorption near-edge structure. Among the supported Pt-Ni catalysts studied, the sandwich bimetallic catalysts demonstrate the highest activity to CO oxidation, where 100% CO conversion occurs near room temperature. Both surface science studies of model catalysts and catalytic reaction experiments on supported catalysts illustrate the synergetic effect of the surface and subsurface Ni species on the CO oxidation, in which the surface Ni oxide nanoislands activate O2, producing atomic O species, while the subsurface Ni atoms further enhance the elementary reaction of CO oxidation with O. © 2011 American Chemical Society.


Liu P.,TU Eindhoven | Li C.,CAS Dalian Institute of Chemical Physics | Hensen E.J.M.,TU Eindhoven
Chemistry - A European Journal | Year: 2012

Efficient basic hydrotalcite (HT)-supported gold nanoparticle (AuNP) catalysts have been developed for the aerobic oxidative tandem synthesis of methyl esters and imines from primary alcohols catalyzed under mild and soluble-base-free conditions. The catalytic performance can be fine-tuned for these cascade reactions by simple adjustment of the Mg/Al atomic ratio of the HT support. The one-pot synthesis of methyl esters benefits from high basicity (Mg/Al=5), whereas moderate basicity greatly improves imine selectivity (Mg/Al=2). These catalysts outperform previously reported AuNP catalysts by far. Kinetic studies show a cooperative enhancement between AuNP and the surface basic sites, which not only benefits the oxidation of the starting alcohol but also the subsequent steps of the tandem reactions. To the best of our knowledge, this is the first time that straightforward control of the composition of the support has been shown to yield optimum AuNP catalysts for different tandem reactions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Liu P.,CAS Dalian Institute of Chemical Physics | Liu P.,TU Eindhoven | Guan Y.,TU Eindhoven | Santen R.A.V.,TU Eindhoven | And 2 more authors.
Chemical Communications | Year: 2011

Chromium (iii)-containing hydrotalcites show strong synergy with gold nanoparticles in achieving high activity in the aerobic oxidation of alcohols. © 2011 The Royal Society of Chemistry.


Yu F.,Dalian University of Technology | Li P.,CAS Dalian Institute of Chemical Physics | Song P.,CAS Dalian Institute of Chemical Physics | Wang B.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemical Communications | Year: 2012

We present a colorimetric and ratiometric fluorescent probe Cy-N 3 that exhibits a selective response to H 2S. The probe employs a near-infrared cyanine as a fluorophore, and is equipped with an operating azide unit. It is readily employed for assessing intracellular H 2S levels, and confocal ratiometric imaging is achieved successfully. This journal is © The Royal Society of Chemistry 2012.


Ji S.,Dalian University of Technology | Wu W.,Dalian University of Technology | Song P.,CAS Dalian Institute of Chemical Physics | Han K.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Journal of Materials Chemistry | Year: 2010

Ru(Phen)(bpy)2 (1) and its new derivatives (2-5) with pyrenyl or ethynylated pyrene and phenyl units appended to the 3-position of the phenanthroline (Phen) ligand were prepared and these complexes generate long-lived room temperature phosphorescence in the red and near IR range (600-800 nm). The photophysical properties of these complexes were investigated by UV-Vis absorption, luminescence emission, transient absorption spectra and DFT/TDDFT calculations. We found the luminescence lifetime (τ)can be drastically extended by ligand modification (increased up to 140-fold), e.g. τ = 58.4 μs for complex 3 (with pyrenyl ethynylene appendents) was found, compared to τ = 0.4 μs for the reference complex 1. Ethynylated phenyl appendents alter the τ also (complex 2, τ = 2.4 μs). With pyrenyl appendents (4 and 5), lifetimes of 2.5 μs and 9.2 μs were observed. We proposed three different mechanisms for the lifetime extension of 2, 3, 4 and 5. For 2, the stabilization of the 3MLCT state by π-conjugation is responsible for the extension of the lifetime. For 3, the emissive state was assigned as an intra-ligand (IL) long-lived 3π-π* state (3IL/3LLCT, intraligand or ligand-to-ligand charge transfer), whereas a C-C single bond linker results in a triplet state equilibrium between 3MLCT state and the pyrene localized 3π-π* triplet state (3IL, e.g.4 and 5). DFT/TDDFT calculations support the assignment of the emissive states. The effects of the lifetime extension on the oxygen sensing properties of these complexes were studied in both solution and polymer films. With tuning the emissive states, and thus extension of the luminescence lifetimes, the luminescent O2 sensing sensitivity of the complexes can be improved by ca. 77-fold in solution (I0/I100 = 1438 for complex 3, vs. I0/I100 = 18.5 for complex 1). In IMPES-C polymer films, the apparent quenching constant KSV app is improved by 150-fold from 0.0023 Torr-1 (complex 1) to 0.35 Torr-1 (complex 3). The KSV app value of complex 3 is even higher than that of PtOEP under similar conditions (0.15 Torr-1). © 2010 The Royal Society of Chemistry.


Guo S.,CAS Dalian Institute of Chemical Physics | Pan X.,CAS Dalian Institute of Chemical Physics | Gao H.,Dalian University of Technology | Yang Z.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemistry - A European Journal | Year: 2010

Carbon nanotubes (CNTs) have been shown to modify some properties of nanomaterials and to modify chemical reactions confined inside their channels, which are formed by curved graphene layers. Here we studied ammonia synthesis over Ru as a probe reaction to understand the effect of the electron structure of CNTs on the confined metal particles and their catalytic activity. The catalyst with Ru nanoparticles dispersed almost exclusively on the exterior nanotube surface exhibits a higher activity than the CNT-confined Ru, although both have a similar metal particle size. Characterization with TEM, N 2 physisorption, H2 chemisorption, temperature-pro-grammed reduction, CO adsorption microcalorimetry, and first-principles calculations suggests that the outside Ru exhibits a higher electron density than the inside Ru. As a result, the dissociative adsorption of N2, which is an electrophilic process and the rate-determining step of ammonia synthesis, is more facile over the outside Ru than that over the inside one. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Qi Z.,Dalian University of Technology | Qi Z.,CAS Dalian Institute of Chemical Physics | Wang M.,Dalian University of Technology | Li X.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2014

A new rhodium-catalyzed synthesis of sultones via the oxidative coupling of sulfonic acids with internal alkynes is described. The reaction proceeds via aryl C-H activation assisted by a sulfonic acid group. This journal is © the Partner Organisations 2014.


Song C.,CAS Dalian Institute of Chemical Physics | Ye Z.,Dalian University of Technology | Wang G.,Dalian University of Technology | Yuan J.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
ACS Nano | Year: 2010

The development of core-shell nanoparticles has shown a wide range of new applications in the fields of chemistry, bioscience, and materials science because of their improved physical and chemical properties over their single-component counterparts. In the present work, we took the core-shell nanoarchitectures as an example to research the luminescence resonance energy transfer (LRET) process between a luminescent Tb3+ chelate, N,N,N1,N1-[4′-phenyl-2,2′:6′,2′- terpyridine-6,6′-diyl]bis(methylenenitrilo)tetrakis(acetate)-Tb 3+ (PTTA-Tb3+), and an organic dye, 5- carboxytetramethylrhodamine (CTMR). PTTA-Tb3+ and CTMR were chosen as the donor-acceptor pair of LRET in our model construction because of their effective spectral overlapping. The core-shell nanoparticles featuring a CTMR-SiO2 core surrounded by a concentric PTTA-Tb3+- SiO2 shell were prepared using a reverse microemulsion method. These nanoparticles are spherical, uniform in size, and highly photostable. The results of LRET experiments show that the sensitized emission lifetime of the acceptor in the nanoparticles is significantly prolonged (∼246 μs), which is attributed to the long emission lifetime of the Tb3+ chelate donor. According to the results of the steady-state and time-resolved luminescence spectroscopy, an energy transfer efficiency of ∼80% and a large Förster distance between the donor and the acceptor in the core-shell nanoparticles are calculated, respectively. The new core-shell nanoparticles with a high LRET efficiency and long Förster distance enable them to be promising optical probes for a variety of possible applications such as molecular imaging and multiplex signaling. © 2010 American Chemical Society.


Yang D.,Dalian University of Technology | Yang D.,CAS Dalian Institute of Chemical Physics | Cong S.-L.,Dalian University of Technology
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

The dissociation dynamics of HD+ molecules is studied theoretically by numerically solving the time-dependent Schrödinger equation in which the molecular vibrational and rotational degrees of freedom are included. Based on the Born-Oppenheimer approximation, the ground 1sσg state and the excited 2pσu state are taken into account, corresponding to two dissociative channels HD +→D + H+ and HD+→H + D+, respectively. Two dissociative nuclear wave packets overlap and interfere after excited by two ultrashort laser pulses. The interference patterns can be controlled by varying the laser parameters and the dissociation probabilities are demonstrated for different laser fields. The kinetic energy-dependent distributions of the fragments are calculated using an asymptotic-flow expression in the momentum space. The branching ratio D+/(H + + D+), as a function of the delay time and the relative phase between two laser pulses, is also discussed. © 2011 American Physical Society.


Cui Y.,CAS Dalian Institute of Chemical Physics | Gao J.,Dalian University of Technology | Jin L.,CAS Dalian Institute of Chemical Physics | Zhao J.,Dalian University of Technology | And 3 more authors.
Nano Research | Year: 2012

A two-dimensional (2D) Si film can form between a graphene overlayer and a Ru(0001) substrate through an intercalation process. At the graphene/2D-Si/Ru(0001) surface, the topmost graphene layer is decoupled from the Ru substrate and becomes quasi-freestanding. The interfacial Si layers show high stability due to the protection from the graphene cover. Surface science measurements indicate that the surface Si atoms can penetrate through the graphene lattice, and density functional theory calculations suggest a Si-C exchange mechanism facilitates the penetration of Si at mild temperatures. The new mechanism may be involved for other elements on graphene, if they can bond strongly with carbon. This finding opens a new route to form 2D interfacial layers between graphene and substrates. © 2012 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.


Zhou X.-Y.,Dalian University of Technology | Bao M.,Dalian University of Technology | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Advanced Synthesis and Catalysis | Year: 2011

Using a catalytic amount of a Brønsted acid as activator of simple imines, the highly enantioselective homogeneous palladium-catalyzed asymmetric hydrogenation of simple ketimines was successfully developed with up to 95% ee. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhou X.-Y.,Dalian University of Technology | Wang D.-S.,CAS Dalian Institute of Chemical Physics | Bao M.,Dalian University of Technology | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Tetrahedron Letters | Year: 2011

Homogeneous Pd(OCOCF3)2/(R)-C4-TunePhos has been successfully applied in the asymmetric hydrogenation of simple ketones activated by catalytic amount of Brønsted acid with up to 88% ee. © 2011 Elsevier Ltd. All rights reserved.


Cao L.-L.,Hunan University | Wang D.-S.,CAS Dalian Institute of Chemical Physics | Jiang G.-F.,Hunan University | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Tetrahedron Letters | Year: 2011

An efficient route to 2,3-disubstituted indoles was developed via reductive alkylation of 2-substituted indoles using hydrogen as a clean and atom economic reductant under ambient pressure. © 2011 Elsevier Ltd. All rights reserved.


Zhang Y.,CAS Dalian Institute of Chemical Physics | Zhang Y.,TU Eindhoven | Degirmenci V.,TU Eindhoven | Li C.,CAS Dalian Institute of Chemical Physics | Hensen E.J.M.,TU Eindhoven
ChemSusChem | Year: 2011

MIL-101, a chromium-based metal-organic framework, is known for its very large pore size, large surface area and good stability. However, applications of this material in catalysis are still limited. 5-Hydroxymethylfurfural (HMF) has been considered a renewable chemical platform for the production of liquid fuels and fine chemicals. Phosphotungstic acid, H3PW 12O40 (PTA), encapsulated in MIL-101 is evaluated as a potential catalyst for the selective dehydration of fructose and glucose to 5-hydroxymethylfurfural. The results demonstrate that PTA/MIL-101 is effective for HMF production from fructose in DMSO and can be reused. This is the first example of the application of a metal-organic framework in carbohydrate dehydration. Solid acid for biomass valorization: Phosphotungstic acid encapsulated in the metal-organic framework MIL-101 is an effective and reusable catalyst for the selective dehydration of fructose to 5-hydroxymethylfurfural, a renewable chemical platform for the production of liquid fuels and fine chemicals. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhao B.,University of New Mexico | Sun Z.,CAS Dalian Institute of Chemical Physics | Guo H.,University of New Mexico
Journal of the American Chemical Society | Year: 2015

Energy flow and sequestration at the state-to-state level are investigated for a prototypical four-atom reaction, H2 + OH' H + H2O, using a transition-state wave packet (TSWP) method. The product state distribution is found to depend strongly on the reactant vibrational excitation, indicating mode specificity at the state-to-state level. From a local-mode perspective, it is shown that the vibrational excitation of the H2O product derives from two different sources, one attributable to the energy flow along the reaction coordinate into the newly formed OH bond and the other due to the sequestration of the vibrational energy in the OH spectator moiety during the reaction. The analysis provided a unified interpretation of some seemingly contradicting experimental observations. It is further shown that the transfer of vibrational energy from the OH reactant to H2O product is gated by the transition state, accomplished coherently by multiple TSWPs with the corresponding OH vibrational excitation. © 2015 American Chemical Society.


Cai X.-F.,CAS Dalian Institute of Chemical Physics | Cai X.-F.,Dalian University of Technology | Guo R.-N.,CAS Dalian Institute of Chemical Physics | Chen M.-W.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemistry - A European Journal | Year: 2014

Asymmetric hydrogenation of aromatic quinolin-3-amines was successfully developed with up to 94% enantiomeric excess (ee). Introduction of the phthaloyl moiety to the amino group is crucial to eliminate the inhibition effect caused by the substrate and product, to activate the aromatic ring, and to improve the diastereoselectivity. This new methodology provides direct and facile access to chiral exocyclic amines. Notably, this report is the first on the highly enantioselective hydrogenation of aromatic amines. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhou X.,CAS Dalian Institute of Chemical Physics | Hensen E.J.M.,TU Eindhoven | Van Santen R.A.,TU Eindhoven | Li C.,CAS Dalian Institute of Chemical Physics
Chemistry - A European Journal | Year: 2014

Density functional theory (DFT) calculations are used to explore water adsorption and activation on different α-Ga2O3 surfaces, namely (001), (100), (110), and (012). The geometries and binding energies of molecular and dissociative adsorption are studied as a function of coverage. The simulations reveal that dissociative water adsorption on all the studied low-index surfaces are thermodynamically favorable. Analysis of surface energies suggests that the most preferentially exposed surface is (012). The contribution of surface relaxation to the respective surface energies is significant. Calculations of electron local density of states indicate that the electron-energy band gaps for the four investigated surfaces appears to be less related to the difference in coordinative unsaturation of the surface atoms, but rather to changes in the ionicity of the surface chemical bonds. The electrochemical computation is used to investigate the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) on α-Ga 2O3 surfaces. Our results indicate that the (100) and (110) surfaces, which have low stability, are the most favorable ones for HER and OER, respectively. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Koekkoek A.J.J.,TU Eindhoven | Xin H.,CAS Dalian Institute of Chemical Physics | Yang Q.,CAS Dalian Institute of Chemical Physics | Li C.,CAS Dalian Institute of Chemical Physics | Hensen E.J.M.,TU Eindhoven
Microporous and Mesoporous Materials | Year: 2011

Different synthetic routes including carbon black and organosilane, templating and desilication were successfully employed to synthesize hierarchical Fe/ZSM-5 zeolites with improved catalytic performance in benzene oxidation to phenol with nitrous oxide. All these mesoporous zeolites show similar crystallinity, which is lower as compared to a conventional Fe/ZSM-5 catalyst. Hierarchical Fe/ZSM-5 catalysts exhibit superior catalytic performance, especially in terms of stability, in the selective oxidation of benzene to phenol with nitrous oxide. The best performance is obtained for the organosilane templated zeolites. The high initial activity and stability are related to the high interconnectivity of the micropores and mesopores, thus limiting the zeolite domain size. This results in enhanced mass transport and prevents fast blocking of the micropore space by carbonaceous byproducts. © 2011 Elsevier Inc. All rights reserved.


Wang Z.,Dalian University of Technology | Zhang B.,Dalian University of Technology | Yu H.,Dalian University of Technology | Sun L.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemical Communications | Year: 2010

Microporous polyimide networks with BET surface areas up to 1407 m 2 g-1 and pore size distribution of 4-8 Å were synthesized. The respective effect of surface area and affinity between hydrogen molecule and polyimides on hydrogen storage properties were investigated. © The Royal Society of Chemistry.


Xu C.,CAS Dalian Institute of Chemical Physics | Xu C.,Dalian University of Technology | Yang W.,CAS Dalian Institute of Chemical Physics | Guo Q.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Journal of the American Chemical Society | Year: 2013

It is well established that adding methanol to water could significantly enhance H2 production by TiO2. Recently, we have found that methanol can be photocatalytically dissociated on TiO2(110) at 400 nm via a stepwise mechanism. However, how molecular hydrogen can be formed from the photocatalyzed methanol/TiO2(110) surface is still not clear. In this work, we have investigated deuterium formation from photocatalysis of the fully deuterated methanol (CD3OD) on TiO 2(110) at 400 nm using a temperature programmed desorption (TPD) technique. Photocatalytic dissociation products formaldehyde (CD2O) and D-atoms on BBO sites (via D2O TPD product) have been detected. In addition to D2O formation by heating the photocatalyzed methanol/TiO2(110) surface, we have also observed D2 product formation. D2 is clearly formed via thermal recombination of the D-atoms on the BBO sites from photocatalysis of methanol. Experimental results indicate that D2O formation is more important than D 2 formation and that D2 formation is clearly affected by the D2O formation process. © 2013 American Chemical Society.


Liu L.,Dalian University of Technology | Liu L.,CAS Dalian Institute of Chemical Physics | Hao J.,Dalian University of Technology | Shi Y.,Dalian University of Technology | And 2 more authors.
RSC Advances | Year: 2015

With the aids of density functional theory (DFT) and time-dependent density functional theory (TD-DFT), the explosives-detection mechanism of a typical luminescent metal-organic framework (MOF) sensor has been comprehensively studied by investigating the interactions between the framework and two analytes, namelty, benzene and nitrobenzene. By studying both the periodic crystal models and cluster models we obtained an in-depth understanding of the detecting mechanism from the viewpoint of electronic coupling between the analyte and sensor. Intermolecular electron transfer from the conduction bands of the framework to the LUMO of nitrobenzene is demonstrated to induce the luminescence quenching phenomenon observed in previous experiments. π-π stacking and hydrogen bonding interactions are found to play essential roles in this intermolecular electron transfer process. π-π stacking provides large fragment orbital overlaps between the unoccupied orbitals of the analyte and sensor, which serves as a highly efficient electron transfer bridge. Hydrogen bonds alone cannot provide enough overlaps for electron transfer but are found to reinforce the π-π stacking interactions. The cooperation of the two interactions induces facile intermolecular electron transfer which strongly quenches the luminescence of the MOF sensor. This work sheds light on the analyte-sensor interactions inside the MOF sensors and would provide valuable insights into the design of high efficient explosivesdetecting MOF sensors. © The Royal Society of Chemistry 2015.


Zhang M.,Liaoning Normal University | Zhang M.,CAS Dalian Institute of Chemical Physics | Lin G.,Dalian University of Technology | Wu B.,CAS Dalian Institute of Chemical Physics | Shao Z.,CAS Dalian Institute of Chemical Physics
Journal of Power Sources | Year: 2012

Thin films of CrN x with different nitrogen contents are deposited on 316L stainless steel (SS316L) as bipolar plates for polymer electrolyte membrane fuel cells (PEMFCs) by arc ion plating (AIP) through adjusting nitrogen gas flow rate. The optimal N 2 flow rate and resultant N content in CrN x films are determined by evaluating the interfacial contact resistance (ICR) between carbon papers and the coated samples, and the corrosion resistance in the simulated PEMFC conditions. After coating CrN x films, the performance of SS316L bipolar plates is obviously improved, and has a close relationship with N content in the CrN x films. Compared with the bare SS316L, the CrN x coated SS316L exhibits a reduced ICR by one order of magnitude and the corrosion resistance increases by two orders of magnitude. The results show that CrN 0.86 film coated SS316L bipolar plates present best performance, i.e. the ICR of CrN 0.86 film coated sample reduces to 8.8 mΩ cm 2 under 1.0 MPa compaction pressure, and the corrosion current density almost reaches 10 -7 A cm -2. The analysis indicates that the enhanced performance of the coated SS316L bipolar plates is related to the high film density determined by AIP, and the variation of phase structure and film composition. © 2012 Elsevier B.V. All rights reserved.


Yang G.,Northeast Forestry University | Yang G.,TU Eindhoven | Zhou L.,Northeast Forestry University | Han X.,CAS Dalian Institute of Chemical Physics
Journal of Molecular Catalysis A: Chemical | Year: 2012

Tetravalent-ion (M 4+)-doped zeolites show excellent performances for a variety of catalytic processes, including the focusing biomass conversions. In this work, density functional calculations were performed to probe the Lewis and Brönsted acidities of various M 4+-doped zeolites as well as to study interactions with probe molecules. The Lewis and Brönsted acidities increase in the orders of Silicalite-1 Ge < Ti < Pb < Sn < Zr and Silicalite-1 Ti < Ge < Zr ≈ B < Pb < Sn < Al, respectively. The Lewis acidities should be defined as the local sites around the M 4+ ions, explaining why the adsorption energies give a more consistent order with LUMO energies and absolute electronegativity rather than fukui functions. The formation of Brönsted acidic sites is facilitated by doping with M 4+ ions. Albeit the Brönsted acidities of these M 4+-doped zeolites change greatly with Sn being the strongest, their strengths are far below that of Al 3+. The interactions of five probe molecules of changing basicities with the Brönsted acidic sites indicate that the formations of covalent and/or ionic structures are the proton-competing results: the covalent and ionic structures co-exist only for trimethyphosphine and pyridine of comparable basicity; otherwise, proton transfer will take place and result in only the ionic or covalent structures. The proton affinity fails to predict the Brönsted acidity of Zr and is evidenced, especially by formation of the covalent structure during pyridine adsorption. Thus, this work presents a dynamic image of acid-base interactions and aids our understanding toward the catalysis of solid-state acids. © 2012 Elsevier B.V.


Cai X.-F.,Dalian University of Technology | Cai X.-F.,CAS Dalian Institute of Chemical Physics | Guo R.-N.,CAS Dalian Institute of Chemical Physics | Feng G.-S.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Organic Letters | Year: 2014

A chiral phosphoric acid catalyzed asymmetric transfer hydrogenation of aromatic amines, quinolin-3-amines, was successfully developed with up to 99% ee. To supplement our previous work on the Ir-catalyzed asymmetric hydrogenation of 2-alkyl substituted quinolin-3-amines, a number of 2-aryl substituted substrates were reduced to provide a series of valuable chiral exocyclic amines with high diastereo- and enantioselectivities. © 2014 American Chemical Society.


Han F.,Dalian University of Technology | Ma L.,CAS Dalian Institute of Chemical Physics | Ma L.,Qufu Normal University | Sun Q.,Dalian University of Technology | And 2 more authors.
Nano Research | Year: 2014

Fe3O4 is a promising high-capacity anode material for lithium ion batteries, but challenges including short cycle life and low rate capability hinder its widespread implementation. In this work, a well-defined tubular structure constructed by carbon-coated Fe3O4 has been successfully fabricated with hierarchically porous structure, high surface area, and suitable thickness of carbon layer. Such purposely designed hybrid nanostructures have an enhanced electronic/ionic conductivity, stable electrode/electrolyte interface, and physical buffering effect arising from the nanoscale combination of carbon with Fe3O4, as well as the hollow, aligned and hierarchically porous architectures. When used as an anode material for a lithium-ion half cell, the carbon-coated hierarchical Fe3O4 nanotubes showed excellent cycling performance with a specific capacity of 1,020 mAh·g−1 at 200 mA·g−1 after 150 cycles, a capacity retention of ca. 103%. Even at a higher current density of 1,000 mA·g−1, a capacity of 840 mAh·g−1 is retained after 300 cycles with no capacity loss. In particular, a superior rate capability can be obtained with a stable capacity of 355 mAh·g−1 at 8,000 mA·g−1. The encouraging results indicate that hierarchically tubular hybrid nanostructures can have important implications for the development of high-rate electrodes for future rechargeable lithium ion batteries (LIBs).[Figure not available: see fulltext.]. © 2014, Tsinghua University Press and Springer-Verlag Berlin Heidelberg.


Chen X.,CAS Dalian Institute of Chemical Physics | Deng D.,CAS Dalian Institute of Chemical Physics | Pan X.,CAS Dalian Institute of Chemical Physics | Hu Y.,Canadian Light Source Inc. | Bao X.,CAS Dalian Institute of Chemical Physics
Chemical Communications | Year: 2014

N-doped graphene used as an efficient electron donor of iron catalysts for CO hydrogenation can achieve a high selectivity of around 50% for light olefins, significantly superior to the selectivity of iron catalysts on conventional carbon materials, e.g. carbon black with a selectivity of around 30% at the same reaction conditions. This journal is © The Royal Society of Chemistry.


Zhanga M.,CAS Dalian Institute of Chemical Physics | Zhanga M.,Liaoning Normal University | Hu L.,Dalian University of Technology | Lin G.,Dalian University of Technology | Shao Z.,CAS Dalian Institute of Chemical Physics
Journal of Power Sources | Year: 2012

Honeycomb-like nanocomposite Ti-Ag-N films are prepared by pulsed bias arc ion plating, and for the first time served as surface modification layer on TA1 titanium as bipolar plates for unitized regenerative fuel cells (URFCs). Phase structure and surface morphology of the coated samples are investigated by XRD and SEM. Corrosion resistance of bare Ti plates and Ti-Ag-N coated samples is evaluated in simulated URFC conditions, and the interface contact resistance (ICR) between bipolar plates and carbon papers is measured before and after potentiostatic polarization tests. Ti2N phase with a preferred orientation of (1 1 0) plane is observed in the Ti-Ag-N film. SEM observation indicates that the film appears honeycomb-like and forms a nanocomposite microstructure with Ag nanoparticles embedded in Ti2N matrix. Compared to bare titanium plates, the coated sample shows improved corrosion resistance and ultra-low ICR (2 mω cm 2 under a compaction pressure of 1.4 MPa). The superior conductivity of the coated sample is attributed to nanocomposite microstructure containing highly conductive Ag nanoparticles, and honeycomb-like rough surface obtained in this study. Nanocomposite Ti-Ag-N coated titanium bipolar plate exhibits prominent interfacial conductivity and excellent corrosion resistance at high potential, being a promising candidate as bipolar plate for applications in URFCs. © 2011 Elsevier B.V. All rights reserved.


Cao L.-L.,Hunan University | Cao L.-L.,CAS Dalian Institute of Chemical Physics | Ye Z.-S.,CAS Dalian Institute of Chemical Physics | Jiang G.-F.,Hunan University | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Advanced Synthesis and Catalysis | Year: 2011

The rhodium-catalyzed addition of arylboronic acids to vinylogous imines generated in situ from sulfonylindoles has been developed. This procedure provided a rapid approach to C-3 sec-alkyl-substituted indoles. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li G.,CAS Dalian Institute of Chemical Physics | Li G.,University of Chinese Academy of Sciences | Pidko E.A.,TU Eindhoven | Van Santen R.A.,TU Eindhoven | And 3 more authors.
Journal of Catalysis | Year: 2011

The stability of isolated extraframework Fe2+ ions in ZSM-5 zeolite and their reactivity in the benzene to phenol oxidation were studied by periodic DFT calculations. Mononuclear iron(II) cations can only be stabilized at very specific exchange sites of ZSM-5 zeolite. Accordingly, iron will be predominantly present as oxygenated/hydroxylated mono- and binuclear iron complexes in Fe/ZSM-5. The reactivity of isolated Fe2+ does not depend on the local coordination environment around iron, whereas the steric constraints imposed by the zeolite lattice are important for the overall catalytic reactivity. [FeO]+, [HOFe(μ-O)FeOH]2+, [Fe(μ-O)2Fe]2+, [Fe(μ-O)Fe]2+ extraframework complexes are also potential sites for benzene activation. The reaction is however not catalytic in these cases because the vacant active site cannot be regenerated. The presence of basic extraframework O ligands in these complexes favors phenol dissociation resulting in the formation of stable grafted phenolate species, and ultimately, to the deactivation of the oxygenated iron complexes. © 2011 Elsevier Inc. All rights reserved.


Xiao Z.,Dalian University of Technology | Jin S.,Dalian University of Technology | Wang X.,Dalian University of Technology | Li W.,Michigan Technological University | And 2 more authors.
Journal of Materials Chemistry | Year: 2012

The Cu-Fe catalysts with stoichiometric proportion (Cu/Fe molar ratio was 0.5) were prepared by an epoxide assisted route. The structural properties of Cu-Fe catalysts were determined by X-ray diffraction (XRD), and Mössbauer spectroscopy measurements. These results indicated that a crystalline phase transformation from c-CuFe 2O 4 to t-CuFe 2O 4 occurred when elevating the calcination temperature from 500 to 600 °C. The M-H plots exhibited that all Cu-Fe catalysts had ferromagnetic nature and the saturation magnetization values monotonously increased with increasing calcination temperature irrespective of the phases composition. The significant superparamagnetic behavior was observed in the results of magnetic and Mössbauer spectroscopy measurements. The H 2 temperature-programmed reduction (H 2-TPR) was also conducted for examining the reducibility of Cu-Fe catalysts. The catalytic performance of Cu-Fe catalysts was examined for the hydrogenolysis reaction of glycerol. It is found that the formation of spinel CuFe 2O 4 greatly enhances the hydrogenolysis activity. The highest glycerol conversion (47%) was obtained over CuFe-500 catalyst, while the selectivity of 1,2-propanediol was maintained at about 92% for all catalysts. © The Royal Society of Chemistry 2012.


Wang R.,Dalian University of Technology | Liu D.,Dalian University of Technology | Ren H.,Dalian University of Technology | Zhang T.,Dalian University of Technology | And 3 more authors.
Advanced Materials | Year: 2011

Highly efficient, orange organic light-emitting diodes (OLEDs) fabricated from newly synthesized iridium complexes show a maximum luminance efficiency of 76 cd A-1 and a peak power efficiency of 45 lm W-1. The white OLEDs containing the orange iridium and traditional blue iridium phosphors exhibit extraordinarily high efficiencies and a peak external quantum efficiency of 26%. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li L.,Dalian University of Technology | Wang T.,Dalian University of Technology | Liu Q.,Dalian University of Technology | Cao Y.,CAS Dalian Institute of Chemical Physics | Qiu J.,Dalian University of Technology
Carbon | Year: 2012

Ordered mesoporous silica/carbon composite membranes with a high CO 2 permeability and selectivity were designed and prepared by incorporating SBA-15 or MCM-48 particles into polymeric precursors followed by heat treatment. The as-made composite membranes were characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and N 2 adsorption, of which the gas separation performance in terms of gas permeability and selectivity were evaluated using the single gas (CO 2, N 2, CH 4) and gas mixtures (CO 2/N 2 and CO 2/CH 4, 50/50 mol.%). In comparison to the pure carbon membranes and microporous zeolite/C composite membranes, the as-made mesoporous silica/C composite membranes, and the MCM-48/C composite membrane in particular, exhibit an outstanding CO 2 gas permeability and selectivity for the separation of CO 2/CH 4 and CO 2/N 2 gas pairs owing to the smaller gas diffusive resistance through the membrane and additional gas permeation channels created by the incorporation of mesoporous silicas in carbon membrane matrix. The channel shape and dimension of mesoporous silicas are key parameters for governing the gas permeability of the as-made composite membranes. The gas separation mechanism and the functions of porous materials incorporated inside the composite membranes are addressed. © 2012 Elsevier Ltd. All rights reserved.


Luo J.,Hunan University | Wu B.,CAS Dalian Institute of Chemical Physics | Chen M.-W.,CAS Dalian Institute of Chemical Physics | Jiang G.-F.,Hunan University | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics
Organic Letters | Year: 2014

A concise synthesis of spiro-cyclopropane compounds from indole derivatives and sulfur ylides has been developed via a dearomatization strategy. Moreover, the spiro-cyclopropane compounds could be conveniently transformed to rearomatized indole derivatives in the presence of acids. © 2014 American Chemical Society.


Wang D.-S.,CAS Dalian Institute of Chemical Physics | Tang J.,Hunan University | Zhou Y.-G.,CAS Dalian Institute of Chemical Physics | Chen M.-W.,CAS Dalian Institute of Chemical Physics | And 3 more authors.
Chemical Science | Year: 2011

Highly enantioselective hydrogenation of 3-(α-hydroxyalkyl)indoles promoted by a Brønsted acid for dehydration to form a vinylogous iminium intermediate in situ was developed with Pd(OCOCF3)2/(R)- H8-BINAP as catalyst with up to 97% ee. This methodology provides an efficient and rapid access to chiral 2,3-disubstituted indolines. © The Royal Society of Chemistry 2011.


Patent
CAS Dalian Institute of Chemical Physics and Petrochina | Date: 2011-06-03

The present invention relates to a method for producing lubricating base oil with a low cloud point and a high viscosity index. In the method, a lubricating base oil with a low pour point, a low cloud point and a high viscosity index is produced by a hydrorefining-isomerization/asymmetrical cracking-hydrofinishing in the presence of hydrogen, wherein a highly waxy heavy fraction oil having an initial boiling point of 300 C. to 460 C., a wax content of 5% or more, a pour point of 20 C. or more and a cloud point of 5 C. or more is used as a raw material, and naphtha and middle fraction oil being co-produced. The method is characterized mainly in the high yield of heavy base oil, a low pour point and cloud point, a high viscosity and viscosity index of the base oil.


Patent
Petrochina and CAS Dalian Institute of Chemical Physics | Date: 2013-07-17

The present invention relates to a method for producing lubricating base oil with a low cloud point and a high viscosity index. In the method, a lubricating base oil with a low pour point, a low cloud point and a high viscosity index is produced by a hydrorefining-isomerization/asymmetrical cracking-hydrofinishing in the presence of hydrogen, wherein a highly waxy heavy fraction oil having an initial boiling point of 300C to 460C, a wax content of 5% or more, a pour point of -20C or more and a cloud point of -5C or more is used as a raw material, and naphtha and middle fraction oil being co-produced. The method is characterized mainly in the high yield of heavy base oil, a low pour point and cloud point, a high viscosity and viscosity index of the base oil.


Song C.,CAS Dalian Institute of Chemical Physics | Ye Z.,Dalian University of Technology | Wang G.,Dalian University of Technology | Yuan J.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemistry - A European Journal | Year: 2010

A lanthanide-complex-based ratiometric luminescence probe specific for peroxynitrite (ONOO-), 4'-(2, 4-dimethoxyphenyl)-2,2':6',2"- terpyridine6,6"-diyl]bis(methylenenitrilo)tetrakis(acetate)-Eu 3+/Tb3+ ([Eu3+/Tb3+ (DTTA)]), has been designed and synthesized. Both [EU3+(DTTA)] and [Tb 3+(DTTA)] are highly water soluble with large stability constants at ≈1020, and strongly luminescent with luminescence quantum yields of 10.0 and 9.9%, respectively, and long lumines-cence lifetimes of 1.38 and 0.26 ms, respectively. It was found that the luminescence of [Tb 3+(DTTA)] could be quenched by ONOO- rapidly and specifically in aqueous buffers, while that of [Eu3+(DTTA)] did not respond to the addition of ONOO-. Thus, by simply mixing [Eu 3+(DTTA)] and [Tb3+(DTTA)] in an aqueous buffer, a ratiometric luminescence probe specific for time-gated luminescence detection of ONOO- was obtained. The performance of [Tb3+(DTTA)] and [Eu3+/ Tb3+(DTTA)] as the probes for luminescence imaging detection of ONOO- in living cells was investigated. The results demonstrated the efficacy and advantages of the new ratiometric luminescence probe for highly sensitive luminescence bioimaging application. © 2010 Wiley-VCH Verlag GmbH & Co. KGuA, Weinheim.


Wang B.,University of St. Andrews | Ma X.,CAS Dalian Institute of Chemical Physics | Caffio M.,University of St. Andrews | Schaub R.,University of St. Andrews | Li W.-X.,CAS Dalian Institute of Chemical Physics
Nano Letters | Year: 2011

The nucleation and growth mechanisms of graphene on Rh(111) via temperature-programmed growth of C2H4 are studied by scanning tunneling microscopy and spectroscopy, and by density functional theory calculations. By combining our experimental and first-principles approaches, we show that carbon nanoislands form in the initial stages of graphene growth, possessing an exclusive size of seven honeycomb carbon units (hereafter labeled as 7C6). These clusters adopt a domelike hexagonal shape indicating that bonding to the substrate is localized on the peripheral C atoms. Smoluchowski ripening is identified as the dominant mechanism leading to the formation of graphene, with the size-selective carbon islands as precursors. Control experiments and calculations, whereby coronene molecules, the hydrogenated analogues of 7C6, are deposited on Rh(111), provide an unambiguous structural and chemical identification of the 7C6 building blocks. © 2011 American Chemical Society.


Yin Z.,CAS Fujian Institute of Research on the Structure of Matter | Zheng Q.,CAS Fujian Institute of Research on the Structure of Matter | Chen S.-C.,CAS Fujian Institute of Research on the Structure of Matter | Cai D.,CAS Fujian Institute of Research on the Structure of Matter | And 2 more authors.
Advanced Energy Materials | Year: 2014

High efficiency and stable polymer solar cells (PSCs) are fabricated by using solution-processed Zn1-xMgxO (ZMO) films as a novel class of cathode buffer layers (CBLs). They have the advantages of tunable bandgaps and energy levels, high optical transparency, and good electron-transporting abilities. PSCs with an optimized ZMO CBL exhibit a high power conversion efficiency of 8.31%, which is much better than those of control devices without a CBL or with a ZnO CBL. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Zhang Z.,South-Central University for Nationalities | Liu B.,South-Central University for Nationalities | Zhao Z.K.,CAS Dalian Institute of Chemical Physics
Starch/Staerke | Year: 2012

Conversion of carbohydrates into HMF in ionic liquids (ILs) catalyzed by HfCl4 has been investigated in search of an efficient and environment-friendly process. The structure of ILs, catalyst loading, and reaction temperature had remarkable effects on this new catalytic system. Under optimal conditions, HMF yield up to 77.5% was obtained from fructose in 30 min at 100°C. Moderate yields of HMF were also obtained from aldohexose such as glucose, cellobiose, even cellulose. Furthermore, a possible mechanism for carbohydrates conversion into HMF catalyzed by HfCl4 was proposed according to the configuration of valence shell of Hf. This work provides a meaningful method for the conversion of carbohydrates into fine chemicals. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Li Y.,CAS Dalian Institute of Chemical Physics | Lee M.L.,Brigham Young University | Jin J.,CAS Dalian Institute of Chemical Physics | Chen J.,CAS Dalian Institute of Chemical Physics
Talanta | Year: 2012

A novel porous poly(ethylene glycol) methacrylate-based monolithic column for normal phase liquid chromatography was prepared by thermally initiated polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and ethylene dimethacrylate (EDMA) in the presence of selected porogens. The monolith was macroscopically homogeneous, had low flow resistance, and did not swell or shrink significantly in solvents of different polarities. Inverse size-exclusion data indicate that the monolith had a total porosity of 79.2%, including an external porosity of 69.3% and an internal porosity of 9.9%. Due to its mild polarity (hydrophilicity), the PEG-functionalized monolith could perform traditional normal phase chromatography using non-polar solvents The van Deemter plot demonstrated that the column efficiency of 33,600-34,320 theoretical plates/m could be achieved at a linear flow velocity of 0.9-1.5 mm/s. The dual retention capability (both weak hydrophilic and hydrophobic interactions) investigated in this paper explains well why the PEG-functionalized monolith could operate in various chromatographic modes. © 2012 Elsevier B.V.


He L.,CAS Dalian Institute of Chemical Physics | He L.,University of Chinese Academy of Sciences | Huang Y.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2012

Free of nobility: A supported nickel catalyst derived from Ni-Al hydrotalcite is a promising candidate to replace noble metals for hydrogen generation from the catalytic decomposition of N 2H 4·H 2O under ambient conditions. The catalyst produces H 2 at 30 °C in 93 % selectivity. The catalytic function is due to the cooperation of highly dispersed Ni nanoparticles and strong basic sites located nearby. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Verevkin S.P.,University of Rostock | Zaitsau D.H.,University of Rostock | Tong B.,CAS Dalian Institute of Chemical Physics | Welz-Biermann U.,CAS Dalian Institute of Chemical Physics
Physical Chemistry Chemical Physics | Year: 2011

Activity coefficients at infinite dilution of some common solvents in a protic ionic liquid ethylammonium nitrate have been measured using well established gas-chromatography-method. This method was possible to apply due to extremely low vapour pressure of ethylammonium nitrate at temperatures below 100 °C. Activity coefficients and separation factors were compared with those for aprotic ionic liquids. A new window for intensive accumulation of thermodynamic properties of protic ionic liquids has been opened. © the Owner Societies 2011.


He L.,CAS Dalian Institute of Chemical Physics | He L.,University of Chinese Academy of Sciences | Huang Y.,CAS Dalian Institute of Chemical Physics | Wang A.,CAS Dalian Institute of Chemical Physics | And 6 more authors.
Journal of Catalysis | Year: 2013

Hydrous hydrazine, such as hydrazine monohydrate (N2H 4·H2O), is a promising hydrogen carrier material due to its high content of hydrogen (8.0 wt%). The decomposition of hydrous hydrazine to H2 with a high selectivity and a high activity under mild conditions is the key to its potential usage as a hydrogen carrier material. Platinum-modified Ni/Al2O3 catalysts (NiPt x/Al2O3) were prepared starting from Ni-Al hydrotalcite and tested in the decomposition of hydrous hydrazine. Compared with Ni/Al2O3, the TOF was enhanced sevenfold over NiPt 0.057/Al2O3; meanwhile, the selectivity to H2 was increased to 98%. Characterization results by means of HAADF-STEM, XRD, and EXAFS revealed the presence of surface Pt-Ni alloy in this Pt-promoted catalyst. The formation of Pt-Ni alloy could significantly weaken the interaction between adspecies produced (including H2 and NH x) and surface Ni atoms, which is confirmed by microcalorimetry and TPD results. The weakening effect could account for the greatly enhanced reaction rate, as well as H2 selectivity on NiPtx/Al 2O3 catalysts. © 2012 Elsevier Inc. All rights reserved.


Zhang T.,CAS Dalian Institute of Chemical Physics | Zhang T.,South-Central University for Nationalities | Qi Z.,CAS Dalian Institute of Chemical Physics | Zhang X.,CAS Dalian Institute of Chemical Physics | And 2 more authors.
Chemistry - A European Journal | Year: 2014

Metal-catalyzed hydroacylation of olefins represents an important atom-economic synthetic process in C-H activation. For the first time highly efficient RhIIICp*-catalyzed hydroacylation was realized in the coupling of N-sulfonyl 2-aminobenzaldehydes with both conjugated and aliphatic olefins, leading to the synthesis of various aryl ketones. Occasionally, oxidative coupling occurred when a silver(I) oxidant was used. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Chen J.-S.,CAS Dalian Institute of Chemical Physics | Chen J.-S.,University of Chinese Academy of Sciences | Zhao G.-J.,CAS Dalian Institute of Chemical Physics | Cook T.R.,University of Utah | And 2 more authors.
Journal of the American Chemical Society | Year: 2013

In this work, spectroscopic techniques and quantum chemistry calculations were used to investigate the photophysical properties of various multinuclear platinum complexes with different conformational geometries. This suite of complexes includes a Pt-pyridyl square, a Pt-carboxylate triangle, and a mixed Pt-pyridyl-carboxylate rectangle, as well as two mononuclear Pt model complexes. Studying the individual molecular precursors in the context of larger assemblies is important to provide a complete understanding of the factors governing the observed photophysical properties of a given system. The absorption and emission bands of the parent linear dipyridyl donor (ligand 1) are largely preserved in the [4 + 4] square and the multicomponent [4 + 2 + 2] rectangle (3 and 4, respectively), with significant red shifts. The [3 + 3] Pt-carboxylate triangle containing p-phthalic acid is nonemissive. Phosphorescence and nanosecond transient spectroscopy on 3 and 4 reveal that the introduction of platinum atoms enhances spin-orbital coupling, thereby increasing the rate of intersystem crossing. This phenomenon is consistent with the low fluorescence quantum yields and short fluorescence lifetimes of 3 and 4. Moreover, the electronic structures for the ground state and low-lying excited states of these compounds were studied using quantum chemistry calculations. The fluorescent states of the platinum complexes are local excited states of ligand-centered π-π* transition features, whereas the nonfluorescent states are intramolecular charge-transfer states. These low-lying intramolecular charge-transfer states are responsible for the nonemissive nature of small molecules 1 and 2 and triangle 5. As the interactions between these components determine the properties of their corresponding assemblies, we establish novel excited-state decay mechanisms which dictate the observed spectra. © 2013 American Chemical Society.


Li Y.,CAS Dalian Institute of Chemical Physics | Xie X.,CAS Dalian Institute of Chemical Physics | Lee M.L.,Brigham Young University | Chen J.,CAS Dalian Institute of Chemical Physics
Journal of Chromatography A | Year: 2011

Hydrophilic C18 monolithic polymer sorbents were synthesized for use in solid phase extraction (SPE) and in capillary liquid chromatography (LC). The approach involved incorporating both hydrophobic and hydrophilic monomers into a monolithic material, by copolymerization of stearyl methacrylate (SMA), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and ethylene dimethacrylate (EDMA) in the presence of selected porogens, to produce translucent mesoporous monolithic materials in bulk (SPE) or white macroporous monoliths inside fused silica capillary columns (capillary LC). A capillary column containing one of the hydrophilic C18 monoliths (i.e. poly(SMA-co-PEGMEMA-co-EDMA) with 15% (w/w) PEGMEMA) demonstrated nearly 35% reduction in retention of polycyclic aromatic compounds and greater than 40% increase in retention of phenols compared to a hydrophobic C18 monolithic column. In addition, the hydrophilic monolith demonstrated significantly improved resolution of phenols. Similar monolithic materials prepared in bulk were ground and sieved to obtain 45-65μm particles with desired rigidity for SPE. To achieve optimum extraction performance for phenols, several parameters, including sample pH and volume, and eluent type and volume, were investigated. Under optimized experimental conditions, the method demonstrated good sensitivity (1.6ng/mL LOD) and linearity (R 2>0.97 for 10-200ng/mL). Again, incorporation of 15% (w/w) PEGMEMA in the monolith increased the extraction efficiency of phenols in water from approximately 20% to 67-92% compared to a hydrophobic C18 monolithic material. Increased wettability of the sorbent by the aqueous sample matrix and the presence of hydrogen-bonding interactions are responsible for the improved retention of polar compounds. © 2011 Elsevier B.V.


Chen C.,CAS Dalian Institute of Chemical Physics | Xu J.,CAS Dalian Institute of Chemical Physics | Zhang Q.,CAS Dalian Institute of Chemical Physics | Ma Y.,Missouri University of Science and Technology | And 2 more authors.
Chemical Communications | Year: 2011

A new type of superhydrophobic material, FP-Co-SiO2 was prepared with organic groups immobilized on the surface of the SiO2-based nanocomposite. This material showed much higher catalytic activity for selective oxidation of hydrocarbons than an equivalent hydrophilic catalyst. © 2011 The Royal Society of Chemistry.


Yu L.,State Key Laboratory of Catalysis | Li W.-X.,State Key Laboratory of Catalysis | Li W.-X.,CAS Dalian Institute of Chemical Physics | Pan X.,State Key Laboratory of Catalysis | Bao X.,State Key Laboratory of Catalysis
Journal of Physical Chemistry C | Year: 2012

The interaction of an Fe atom, an Fe dimer, a one-dimensional Fe nanowire, and an FeO nanowire with a single-walled armchair carbon nanotube (CNT) (8, 8) is investigated using density functional theory calculations. The results show that for all iron species the bonding with the outside wall of the CNT is stronger than that with the inside wall. Analysis of the electron distribution of the CNT shows that the curvature of the CNT induces a significant electron disparity at the inside and outside regions and more electrons are distributed on the outer surface. The properties of the frontier orbitals of the CNT are studied, and the results show that the highest occupied molecular orbital and lowest unoccupied molecular orbital are mainly located outside the tube, which may account for the in- and out-dependent interactions of Fe species with the CNT surface and hence different chemical reactivities of CNT-loaded metals. © 2012 American Chemical Society.


Zhang Y.,Yangzhou University | Shi Q.,CAS Dalian Institute of Chemical Physics | Schliesser J.,Brigham Young University | Woodfield B.F.,Brigham Young University | Nan Z.,Yangzhou University
Inorganic Chemistry | Year: 2014

Normal spinel zinc ferrite (ZnFe2O4) nanoparticles (NPs) with zero net magnetization were synthesized by a facile coprecipitation method in which two kinds of organic alkali, namely, 1-amino-2-propanol (MIPA) and bis(2-hydroxypropyl)-amine (DIPA), were used. The diameters of the ZnFe2O4 NPs were determined to be about 7 and 9 nm for samples prepared with MIPA and DIPA, respectively, and the normal spinel structure was confirmed by the magnetic property measurement at room temperature and the temperature dependence of the direct current magnetization. These results are different from those reported in the literature, where ZnFe2O4 NPs show a nonzero net magnetization. The heat capacity of the ZnFe2O4 NPs synthesized using DIPA was measured using a physical property measurement system in the temperature range from 2 to 300 K, and the thermodynamic functions were calculated based on the curve fitting of the experimental heat capacity data. The heat capacity of the ZnFe2O4 NPs was compared with that of a nanosized (Zn0.795Fe0.205)[Zn0.205Fe1.795]O4 material studied in the literature, indicating that the Debye temperature of the present sample is more comparable with that of the bulk ZnFe2O4 reported by Westrum et al. © 2014 American Chemical Society.


Pang J.,CAS Dalian Institute of Chemical Physics | Pang J.,University of Chinese Academy of Sciences | Wang A.,CAS Dalian Institute of Chemical Physics | Zheng M.,CAS Dalian Institute of Chemical Physics | And 5 more authors.
Green Chemistry | Year: 2012

Robust and highly active Ni-based bimetallic catalysts supported on mesoporous carbon have been developed for catalytic conversion of cellulose to hexitols, over which the maximum hexitol yield reached 59.8%. © The Royal Society of Chemistry 2012.