Yu Q.,Key Laboratory of Mesoscopic Chemistry |
Liu L.,Key Laboratory of Mesoscopic Chemistry |
Dong L.,Key Laboratory of Mesoscopic Chemistry |
Li D.,Key Laboratory of Mesoscopic Chemistry |
And 5 more authors.
Applied Catalysis B: Environmental | Year: 2010
Effects of Ce/Zr ratio on the physicochemical properties of CuO/CexZr1-xO2/γ-Al2O3 catalysts were investigated by BET, XRD, Raman and H2-TPR. The catalytic activity and the interaction between the reactants with these catalysts were compared by NO + CO model reaction and in situ FT-IR. The results suggested that the addition of ceria-zirconia mixed oxides significantly improved NO conversion and N2 yield due to dispersed copper species in proximity to ceria-zirconia. Especially, the ceria-rich catalysts displayed better performance in activity and reducibility than others, which would be resulted from the strong interaction among copper, ceria-zirconia and support. The IR results suggested NO reduction activity was correlated with the presence of Cu+ carbonyl species, and the catalysts with variable Ce/Zr ratios had no distinction at the adsorption type and rate of NO/CO at room temperature. However, on heating treatment would give distinct difference in CO2 intensity and the wavenumber of adsorbed nitrates. Simultaneously, the stability of these N- and C-containing intermediates contacted with alumina was influenced by the modified Ce/Zr ratio. © 2010 Elsevier B.V. All rights reserved.
Xing L.,Nanjing University |
Peng L.,Key Laboratory of Mesoscopic Chemistry |
Gu M.,Nanjing University |
Tang G.,Nanjing University
Journal of Alloys and Compounds | Year: 2010
Lutetium aluminum garnet (LuAG) nanopowders were successfully synthesized by a solvothermal method using ethylenediamine as a solvent. We found that the reaction medium, the reaction temperature and the holding time are important factors during the synthesis of LuAG nanopowders. Optimum preparation conditions were obtained in this work. The synthesized LuAG nanopowders are single-phase with desirable properties such as good dispersivity, no aggregation, fine spherical grains and a relatively narrow grain size distribution suggesting that the LuAG nanopowders are promising for application in the compacting and sintering of ceramics. This solvothermal synthesis route provides a new approach for the preparation of LuAG nanopowders at low temperatures. © 2009 Elsevier B.V. All rights reserved.
Han J.,Key Laboratory of Mesoscopic Chemistry |
Han J.,Nanjing University |
Deng C.,Key Laboratory of Mesoscopic Chemistry |
Deng C.,Nanjing University |
And 6 more authors.
Science China Chemistry | Year: 2010
Three tripod molecules, tris(2-methoxy-5-nitrobenzyl)phosphine oxide (1), tris(2-butoxy-3-methyl-5-nitrobenzyl)phosphine oxide (2), and tris(3-nitrobenzyl)amine (TNBA), were synthesized and crystallized. The structures of 1, 2 and their comparison (TNBA) were determined by X-ray crystallography. It is noteworthy that compound 1 interacted with adjacent molecules via π-π stacking and C--H⋯π interactions to yield an open supramolecular network with the porosity P in 8.9%, whereas compound 2 gathered closely to form an open-dimer capsule by sixfold N-O⋯π and triple C-H⋯O interactions, which showed a rare example of a stable in, out-invertomer of phosphine inversion existing in open-dimers. A series of columns were built and arranged side by side by these weak interactions. By contrast, TNBA crystallized to form a 2D network maintained by C-H⋯O and C-H⋯π interactions. It seems minor changes of the chemical structure may cause large differences in the crystal structure and interactions in crystal engineering. © Science China Press and Springer-Verlag Berlin Heidelberg 2010.
Liu Z.,Key Laboratory of Mesoscopic Chemistry |
Ma J.,Key Laboratory of Mesoscopic Chemistry
Science China Chemistry | Year: 2014
The dynamic transformations of conformations and aromatic properties of octaphyrins(220.127.116.11.18.104.22.168) through rotating the pyrrolic ring of the macrocycles are demonstrated by theoretical simulations in CH2Cl2 solution. Facile multistep isomerizations involving antiaromatic-Hückel and aromatic-Möbius topologies were also predicted by density functional theory (DFT). The understanding of changes in topologies and aromaticities of free-base expanded porphrins may provide useful information to build new macrocycles with unique properties. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg.
Yang J.,Key Laboratory of Mesoscopic Chemistry |
Zhou Y.,Key Laboratory of Mesoscopic Chemistry |
Yang J.Y.,Key Laboratory of Mesoscopic Chemistry |
Lin W.G.,Key Laboratory of Mesoscopic Chemistry |
And 4 more authors.
Journal of Physical Chemistry C | Year: 2010
The activity of zeolite MCM-22 in trapping nitrosamines, a class of well-known carcinogenic environmental pollutants, is reported in this article for the first time. MCM-22 possesses a set of unique porous structures and morphologies, making it possible to trap both volatile nitrosamines and bulky tobacco specific nitrosamines. Liquid adsorption and instantaneous gaseous adsorption methods have been employed to study the impact of morphology on MCM-22's ability in adsorbing nitrosamines in both gaseous and liquid media. As-synthesized MCM-22 was subjected to different treatments to induce morphological changes. SEM revealed a special rose-like appearance. The effects of these morphological modifications on MCM-22's adsorption capacities was studied and compared to NaY and NaZSM-5. The results obtained seem to suggest that enhanced collision probability between adsorbate and adsorbent may have an important role to play for MCM-22. Furthermore, the treatments created mesopores in MCM-22 that enhance mass transport within its hierarchical structure. © 2010 American Chemical Society.