The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis ...The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis diffuse reflection spectroscopy, surface photovoltage spectroscopy (SPS). The activities of TiO2 and Gd3+-doped TiO2 catalysts for photocatalytic degradation of ethylene were studied by means of in situ FTIR. The photocatalytic reaction rate constant of ethylene becomes larger through Gd3+ doping. The rate constant of TiO2 was k1=8.51×10-4 min-1, while that of Gd/TiO2 was k2=1.85×10-3 min-1. At the same time, the yield of CO2 increased with Gd3+ doping. The enhancement in photocatalytic activity is probably due to the increase of light absorption, higher content of anatase, smaller crystal line size and higher specific surface area. In addition, the higher photocatalytic activity of Gd3+-doped TiO2 might be attributed to the effective separation of photo-generated electron-hole pairs.展开更多
The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibit...The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.展开更多
文摘The Gd3+-doped TiO2 photocatalyst was prepared by the sol-gel and impregnation method. The effect of Gd3+ doping on crystalline size, BET surface area and photocatalytic activity was studied by XRD, FTIR, BET, UV-Vis diffuse reflection spectroscopy, surface photovoltage spectroscopy (SPS). The activities of TiO2 and Gd3+-doped TiO2 catalysts for photocatalytic degradation of ethylene were studied by means of in situ FTIR. The photocatalytic reaction rate constant of ethylene becomes larger through Gd3+ doping. The rate constant of TiO2 was k1=8.51×10-4 min-1, while that of Gd/TiO2 was k2=1.85×10-3 min-1. At the same time, the yield of CO2 increased with Gd3+ doping. The enhancement in photocatalytic activity is probably due to the increase of light absorption, higher content of anatase, smaller crystal line size and higher specific surface area. In addition, the higher photocatalytic activity of Gd3+-doped TiO2 might be attributed to the effective separation of photo-generated electron-hole pairs.
基金financially supported by the National Natural Science Foundation of China (No. 21573101)the Liaoning Provincial Natural Science Foundation (No. 2014020107)+1 种基金the Program for Liaoning Excellent Talents in Universities (No. LJQ2014041)sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (SRF for ROCS, SEM)
文摘The adsorption of acetonitrile, the co-adsorption of acetonitrile with CO, and hydrogenation of acetonitrile on fresh Mo2C/γ-Al2O3 catalyst were studied by in situ IR spectroscopy. It was found out that CH3CN exhibited strong interaction with the fresh Mo2C/γ-Al2O3 catalyst and was adsorbed mainly on Moδ+ sites of fresh Mo2C/γ-Al2O3 catalyst. Moreover, CH3CN could affect the shifting of IR spectra for CO adsorption towards a lower wave number. The IR spectroscopic study on acetonitrile hydrogenation showed that CH3CN could be easily hydrogenated in the presence of H2 on the Mo2C/γ-Al2O3 catalyst. Furthermore, it was observed that CH3 CN could be selectively hydrogenated to imines on fresh Mo2C/γ-Al2O3 catalyst. Additionally, the active sites of fresh Mo2C/γ-Al2O3 catalyst might be covered with coke during the hydrogenation reaction of acetonitrile. The treatment of catalyst with hydrogen at 673 K could not completely remove coke deposits on the surface of the Mo2C/γ-Al2O3 catalyst.
