An immature pinecone shaped hierarchically structured zirconia （ZrO2-ipch） and a cobblestone-like zirconia nanoparticulate （ZrO2-cs）, both with the monoclinic phase （m-phase）, were synthesized by the facile hydr...An immature pinecone shaped hierarchically structured zirconia （ZrO2-ipch） and a cobblestone-like zirconia nanoparticulate （ZrO2-cs）, both with the monoclinic phase （m-phase）, were synthesized by the facile hydrothermal method and used as the support for a Ni catalyst for the dry reforming of methane （DRM） with CO2. ZrO2-ipch is a much better support than ZrO2-cs and the traditional ZrO2 irregular particles made by a simple precipitation method （ZrO2-ip）. The supported Ni catalyst on ZrO2-ipch （Ni/ZrO2-ipch） exhibited outstanding catalytic activity and coke-resistant stability compared to the ones on ZrO2-cs （Ni/ZrO2-cs） and ZrO2-ip （Ni/ZrO2-ip）. Ni/ZrO2-ip exhibited the worst catalytic performance. The origin of the significantly enhanced catalytic performance was revealed by characterization including XRD, N2 adsorption measurement （BET）, TEM, H2-TPR, CO chemisorption, CO2-TPD, XPS and TGA. The superior catalytic activity of Ni/ZrO2-ipch to Ni/ZrO2-cs or Ni/ZrO2-ip was ascribed to a higher Ni dispersion, increased reducibility, enhanced oxygen mo- bility, and more basic sites with a higher strength, which were due to the unique hierarchically structural morphology of the ZrO2-ipch support. Ni/ZrO2-ipch exhibited better stability for the DRM reaction than Ni/ZrO2-ip, which was ascribed to its higher resistance to Ni sintering due to a strengthened metal-support interaction and the confinement effect of the mesopores and coke deposition resistance. The higher coking resistance of Ni/ZrO2-ipch for the DRM reaction in comparison with Ni/ZrOz-ip orignated from the coke-removalabitity of the higher amount of lattice oxygen and more basic sites, confirmed by XPS and CO2-TPD analysis, and the stabilized Ni on the Ni/ZrO2-ipch catalyst by the confinement effect of the mesopores of the hierarchical ZrO2-ipch sup- port. The superior catalytic performance and coking resistance of the Ni/ZrO2-ipch catalyst makes it a promising candidate for synthesis gas production from the DRM reaction.展开更多
By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the anal...By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.展开更多
A variety of barium sulfate(BaSO4) carriers with or without mesopore structure were synthesized via precipitation reaction in aqueous solution of barium hydroxide and sulfuric acid with ethylene glycol as a modifying ...A variety of barium sulfate(BaSO4) carriers with or without mesopore structure were synthesized via precipitation reaction in aqueous solution of barium hydroxide and sulfuric acid with ethylene glycol as a modifying agent, and then calcined at various temperatures. The obtained BaSO4 was used as catalyst carriers for polystyrene(PS) hydrogenation, and BaSO4 supported palladium(Pd) catalysts with Pd content of 5wt% were prepared by using impregnation method. N2 physisorption, transmission electron microscopy, X-ray diffraction and kinetics studies were used to investigate the effect of carrier structure on the dispersion and geometric location of active metal and their catalytic activities in PS hydrogenation. It was found that the pore structure of carrier played an important role in the dispersion and location of Pd grains. The activation energy values for all the Pd/BaSO4 catalysts were around 49.1kJ/mol, while the pre-exponential factor for Pd/BSC-6H was much higher than others. The Pd/BSC-6H without mesopores had Pd grains deposited on the external surface of the carrier, and exhibited better activity than the mesoporous catalysts. It is indicated that the utilization of Pd/BSC-6H can reduce the pore diffusion of PS coils and enabled more active sites to participate in the PS hydrogenation.展开更多
基金financially supported by the Joint Fund of Coal, set up by National Natural Science Foundation of China and Shenhua Co., Ltd.(U1261104)the National Natural Science Foundation of China (21276041)+3 种基金the Program for New Century Excellent Talents in University (NCET-12-0079)the Natural Science Foundation of Liaoning Province (2015020200)the Fundamental Research Funds for the Central Universities (DUT15LK41)the Science and Technology Development Program of Hangzhou (20130533B14)~~
文摘An immature pinecone shaped hierarchically structured zirconia （ZrO2-ipch） and a cobblestone-like zirconia nanoparticulate （ZrO2-cs）, both with the monoclinic phase （m-phase）, were synthesized by the facile hydrothermal method and used as the support for a Ni catalyst for the dry reforming of methane （DRM） with CO2. ZrO2-ipch is a much better support than ZrO2-cs and the traditional ZrO2 irregular particles made by a simple precipitation method （ZrO2-ip）. The supported Ni catalyst on ZrO2-ipch （Ni/ZrO2-ipch） exhibited outstanding catalytic activity and coke-resistant stability compared to the ones on ZrO2-cs （Ni/ZrO2-cs） and ZrO2-ip （Ni/ZrO2-ip）. Ni/ZrO2-ip exhibited the worst catalytic performance. The origin of the significantly enhanced catalytic performance was revealed by characterization including XRD, N2 adsorption measurement （BET）, TEM, H2-TPR, CO chemisorption, CO2-TPD, XPS and TGA. The superior catalytic activity of Ni/ZrO2-ipch to Ni/ZrO2-cs or Ni/ZrO2-ip was ascribed to a higher Ni dispersion, increased reducibility, enhanced oxygen mo- bility, and more basic sites with a higher strength, which were due to the unique hierarchically structural morphology of the ZrO2-ipch support. Ni/ZrO2-ipch exhibited better stability for the DRM reaction than Ni/ZrO2-ip, which was ascribed to its higher resistance to Ni sintering due to a strengthened metal-support interaction and the confinement effect of the mesopores and coke deposition resistance. The higher coking resistance of Ni/ZrO2-ipch for the DRM reaction in comparison with Ni/ZrOz-ip orignated from the coke-removalabitity of the higher amount of lattice oxygen and more basic sites, confirmed by XPS and CO2-TPD analysis, and the stabilized Ni on the Ni/ZrO2-ipch catalyst by the confinement effect of the mesopores of the hierarchical ZrO2-ipch sup- port. The superior catalytic performance and coking resistance of the Ni/ZrO2-ipch catalyst makes it a promising candidate for synthesis gas production from the DRM reaction.
基金Sponsored by the National 863 Project of China (Grant No. 863 -2 -416)
文摘By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.
基金Supported by the Non-governmental International Science and Technology Cooperation Program from the Science and Technology Commission of Shanghai Municipality(No.10520706000)Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20110074110012)State Key Laboratory of Chemical Engineering Open Fund(No.SKL-ChE09C07)
文摘A variety of barium sulfate(BaSO4) carriers with or without mesopore structure were synthesized via precipitation reaction in aqueous solution of barium hydroxide and sulfuric acid with ethylene glycol as a modifying agent, and then calcined at various temperatures. The obtained BaSO4 was used as catalyst carriers for polystyrene(PS) hydrogenation, and BaSO4 supported palladium(Pd) catalysts with Pd content of 5wt% were prepared by using impregnation method. N2 physisorption, transmission electron microscopy, X-ray diffraction and kinetics studies were used to investigate the effect of carrier structure on the dispersion and geometric location of active metal and their catalytic activities in PS hydrogenation. It was found that the pore structure of carrier played an important role in the dispersion and location of Pd grains. The activation energy values for all the Pd/BaSO4 catalysts were around 49.1kJ/mol, while the pre-exponential factor for Pd/BSC-6H was much higher than others. The Pd/BSC-6H without mesopores had Pd grains deposited on the external surface of the carrier, and exhibited better activity than the mesoporous catalysts. It is indicated that the utilization of Pd/BSC-6H can reduce the pore diffusion of PS coils and enabled more active sites to participate in the PS hydrogenation.
