Zhang J.,Max Planck Institute for Polymer Research |
Zhu Z.,Shanxi Institute of Coal CAS Chemistry |
Tang Y.,Shanghai JiaoTong University |
Mullen K.,Max Planck Institute for Polymer Research |
Feng X.,Max Planck Institute for Polymer Research
Advanced Materials | Year: 2014
Two-dimensional titania nanosheets have been utilized to fabricate 2D titania-based mesoporous silica through a controlled sol-gel method, which can further serve as a robust and versatile template to construct various 2D heterostructures via a nanocasting technology. 2D titania-based CdS has been fabricated. This heterostructure manifests an excellent H2-production rate of 285 μmol·h-1 under visible-light irradiation and an apparent quantum yield of 6.9% at 420 nm. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Luo Q.,Leibniz Institute for Catalysis at the University of Rostock |
Feng G.,Shanxi Institute of Coal CAS Chemistry |
Beller M.,Leibniz Institute for Catalysis at the University of Rostock |
Jiao H.,Leibniz Institute for Catalysis at the University of Rostock
Journal of Physical Chemistry C | Year: 2012
Spin-polarized density functional theory calculations have been performed to investigate formic acid dehydrogenation into carbon dioxide and hydrogen (HCO 2H → CO 2 + H 2) on Ni(111). It is found that formic acid prefers the O (O=C) atop adsorption on nickel surface and the H (H-O) atom bridging two neighboring nickel atoms, and formate prefers the bidentate adsorption with O atop on nickel surface. The computed stretching frequencies for deuterated formic acid (DCO 2H) and deuterated formate (DCO 2) on Ni(111) agree well with the experimentally observed IR spectra. Formic acid dehydrogenation into surface formate and hydrogen atom (HCO 2H → HCO 2 + H) has barrier of 0.41 eV and is exothermic by 0.35 eV. Formate dehydrogenation into carbon dioxide and hydrogen atom (HCO 2 → CO 2 + H) has an effective barrier of about 1.0 eV and is the rate-determining step. Our computed adsorption configurations and energetic data for formic acid dehydrogenation on Ni(111) are very close to the reported results for Pt(111), but in sharp contrast to the previously reported results for Pd(111). Our recalculated adsorption configurations and energetic data for formic acid dehydrogenation on Pd(111) are similar to those on Ni(111) and Pt(111), demonstrating the high similarities of these metals. These computed data show that Pd-catalyzed formic acid dehydrogenation has the lowest effective barrier (0.76 eV), followed by Ni (1.03 eV) and Pt (1.56 eV). © 2012 American Chemical Society.
Huang J.-Q.,Tsinghua University |
Zhuang T.-Z.,Tsinghua University |
Zhang Q.,Tsinghua University |
Peng H.-J.,Tsinghua University |
And 2 more authors.
ACS Nano | Year: 2015
Lithium-sulfur batteries hold great promise for serving as next generation high energy density batteries. However, the shuttle of polysulfide induces rapid capacity degradation and poor cycling stability of lithium-sulfur cells. Herein, we proposed a unique lithium-sulfur battery configuration with an ultrathin graphene oxide (GO) membrane for high stability. The oxygen electronegative atoms modified GO into a polar plane, and the carboxyl groups acted as ion-hopping sites of positively charged species (Li+) and rejected the transportation of negatively charged species (Sn 2-) due to the electrostatic interactions. Such electrostatic repulsion and physical inhibition largely decreased the transference of polysulfides across the GO membrane in the lithium-sulfur system. Consequently, the GO membrane with highly tunable functionalization properties, high mechanical strength, low electric conductivity, and facile fabrication procedure is an effective permselective separator system in lithium-sulfur batteries. By the incorporation of a permselective GO membrane, the cyclic capacity decay rate is also reduced from 0.49 to 0.23%/cycle. As the GO membrane blocks the diffusion of polysulfides through the membrane, it is also with advantages of anti-self-discharge properties. © 2015 American Chemical Society.
Guo X.,Shanxi Institute of Coal CAS Chemistry |
Hao C.,Shanxi Institute of Coal CAS Chemistry |
Jin G.,Shanxi Institute of Coal CAS Chemistry |
Zhu H.-Y.,Queensland University of Technology |
Guo X.-Y.,Shanxi Institute of Coal CAS Chemistry
Angewandte Chemie - International Edition | Year: 2014
Copper is a low-cost plasmonic metal. Efficient photocatalysts of copper nanoparticles on graphene support are successfully developed for controllably catalyzing the coupling reactions of aromatic nitro compounds to the corresponding azoxy or azo compounds under visible-light irradiation. The coupling of nitrobenzene produces azoxybenzene with a yield of 90 % at 60 °C, but azobenzene with a yield of 96 % at 90 °C. When irradiated with natural sunlight (mean light intensity of 0.044 W cm-2) at about 35 °C, 70 % of the nitrobenzene is converted and 57 % of the product is azobenzene. The electrons of the copper nanoparticles gain the energy of the incident light through a localized surface plasmon resonance effect and photoexcitation of the bound electrons. The excited energetic electrons at the surface of the copper nanoparticles facilitate the cleavage of the N=O bonds in the aromatic nitro compounds. Hence, the catalyzed coupling reaction can proceed under light irradiation and moderate conditions. This study provides a green photocatalytic route for the production of azo compounds and highlights a potential application for graphene. Green, light-assisted catalysis: Graphene-supported copper nanoparticles are used as photocatalysts. The photocatalysts can controllably reduce nitroaromatics to corresponding azoxy and azo compounds (see picture) under visible-light irradiation. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
He M.,Sinopec |
He M.,East China Normal University |
Sun Y.,CAS Shanghai Advanced Research Institute |
Sun Y.,Shanxi Institute of Coal CAS Chemistry |
Han B.,CAS Beijing National Laboratory for Molecular
Angewandte Chemie - International Edition | Year: 2013
How green was my valley: Green carbon science focuses on the transformations of carbon-containing compounds in the entire carbon cycle. The ultimate aim is to use carbon resources efficiently and minimize the net CO 2 emission. This holistic view also has ramifications for related fields including petroleum refining and the production of liquid fuels and chemicals from coal, methane, CO2, and biomass. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Liu Z.,Beijing University of Chemical Technology |
Shi S.,China Coal Research Institute |
Li Y.,Shanxi Institute of Coal CAS Chemistry
Chemical Engineering Science | Year: 2010
With fast increasing demand in liquid transportation fuels, limited and unevenly distributed petroleum resources, and volatile petroleum prices, coal liquefaction technologies have again received the world's attention since the beginning of this century. China has actively pursued R&D of coal liquefaction technologies in the past decade and is deploying the first and the largest direct coal liquefaction plant since WWII and the largest indirect coal liquefaction plants after Sasol, South Africa. This paper analyzes the historical developments of coal liquefaction technologies from science point of view, presents recent developments of the technologies in China, and identifies challenges of the technologies towards successful industrial application. © 2009 Elsevier Ltd. All rights reserved.
Zhai D.,Argonne National Laboratory |
Wang H.-H.,Argonne National Laboratory |
Yang J.,Argonne National Laboratory |
Lau K.C.,Argonne National Laboratory |
And 4 more authors.
Journal of the American Chemical Society | Year: 2013
In this paper we report on a kinetics study of the discharge process and its relationship to the charge overpotential in a Li-O2 cell for large surface area cathode material. The kinetics study reveals evidence for a first-order disproportionation reaction during discharge from an oxygen-rich Li2O2 component with superoxide-like character to a Li2O2 component. The oxygen-rich superoxide-like component has a much smaller potential during charge (3.2-3.5 V) than the Li 2O2 component (∼4.2 V). The formation of the superoxide-like component is likely due to the porosity of the activated carbon used in the Li-O2 cell cathode that provides a good environment for growth during discharge. The discharge product containing these two components is characterized by toroids, which are assemblies of nanoparticles. The morphologic growth and decomposition process of the toroids during the reversible discharge/charge process was observed by scanning electron microscopy and is consistent with the presence of the two components in the discharge product. The results of this study provide new insight into how growth conditions control the nature of discharge product, which can be used to achieve improved performance in Li-O2 cell. © 2013 American Chemical Society.
Inagaki M.,Hokkaido University |
Qiu J.,Dalian University of Technology |
Guo Q.,Shanxi Institute of Coal CAS Chemistry
Carbon | Year: 2015
Carbon foams are reviewed by focusing on their preparation and application. Their preparation processes are discussed by classifying them into five categories: blowing and carbonization, template carbonization, compression of exfoliated graphite, assembly of graphene nanosheets and others. Through these processes, density of the foam, sizes of cells and windows, as well as physical properties, are successfully controlled. Carbon foams are expected to give certain contributions to modern technology as containers for active materials for thermal energy storage, electrodes of electrochemical devices and electric energy storage, adsorbents for large molecules, and others including microwave absorption. © 2015 Elsevier Ltd. All rights reserved.
Shen W.,Shanxi Institute of Coal CAS Chemistry |
Fan W.,Shanxi Institute of Coal CAS Chemistry
Journal of Materials Chemistry A | Year: 2013
Nitrogen-containing porous carbon materials are ubiquitous with a wide range of technologically important applications, including separation science, heterogeneous catalyst supports, water purification, electrochemistry, as well as the developing areas of energy generation and storage applications. To date, a variety of approaches has been developed and applied to introduce nitrogen into the carbon matrix. It is important and necessary to design and control a hierarchical porous structure and the surface chemical groups of nitrogen-containing porous carbons for their applications. In this work, we summarize and compare recently reported routes for the preparation of nitrogen-containing porous carbon materials and the effect of nitrogen groups on its applications in adsorption, electrochemistry, catalysis/catalyst supports and hydrogen storage properties. © The Royal Society of Chemistry 2013.
Guo J.,Shanxi Institute of Coal CAS Chemistry |
Guo J.,University of Chinese Academy of Sciences |
Lu C.,Shanxi Institute of Coal CAS Chemistry
Carbon | Year: 2012
The simple and continuous deposition of carbon nanotubes onto the surface of carbon fiber tows, using ethanol as a dispersive medium, was achieved by the electrophoretic process. The resulting materials showed a uniform distribution of carbon nanotubes on the fiber surface. Such a continuous process provides industrial potential for preparing a multiscale carbon nanotube-carbon fiber reinforcement. © 2012 Elsevier Ltd. All rights reserved.