文献类型：期刊文献

英文题名：Promotional effect of Y2O3 on the performance of Ag/α-Al2O3 catalyst for epoxidation of propylene with molecular oxygen

作者：Yao, Wei[1]; Lu, Guanzhong[1]; Guo, Yanglong[1]; Guo, Yun[1]; Wang, Yanqin[1]; Zhang, Zhigang[1]

机构：[1] Lab of Advanced materials, Research Institute of Industrial Catalysis, East China University of Science and Technology, Shanghai, 200237, China

年份：2007

卷号：276

期号：1-2

起止页码：162

外文期刊名：Journal of Molecular Catalysis A: Chemical

收录：EI(收录号：20073710813495)

语种：英文

外文关键词：Alumina - Catalysts - Epoxidation - Molecular oxygen - Propylene - Scanning electron microscopy - Silver - X ray diffraction

摘要：The Ag/α-Al2O3 catalysts modified with rare earth, alkali and alkaline earth metal oxides for the epoxidation of propylene by molecular oxygen were prepared and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), CO2-temperature programmed desorption (CO2-TPD), BET surface area and pore diameter distribution. The results show that the appropriate pore diameter and high surface area of α-Al2O3 support, and the suitable basic sites on the surface of catalyst are necessary to the highly effective Ag catalyst for the epoxidation of propylene. The presence of a small quantity of Y2O3 can restrain the sintering of Ag particles on the surface of α-Al2O3 and adjust the surface basicity of catalyst. The loadings of promoters and reaction temperature obviously affect the performance of Ag catalysts. Under the reaction condition of 0.1 MPa, 245 °C, space velocity 2000 h-1 and the feed of 20% C3H6/8% O2/N2, 4% conversion of propylene and 46.8% selectivity to propylene oxide were obtained over the 20 wt% Ag-0.1% Y2O3-0.1% K2O/α-Al2O3 catalyst. ? 2007 Elsevier B.V. All rights reserved.