Promotional effect of Y2O3 on the performance of Ag/alpha-Al2O3 catalyst for epoxidation of propylene with molecular oxygen

作者：Yao Wei; Lu Guanzhong^*; Guo Yanglong; Guo Yun; Wang Yanqin; Zhang Zhigang

来源：Journal of Molecular Catalysis A: Chemical , 2007, 276(1-2): 162-167.

DOI：10.1016/j.molcata.2007.07.011

• silver/alumina catalyst
• Y2O3 promoter
• epoxidation of propylene
• molecular oxygen

The Ag/alpha-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 alpha-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 alpha-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 degrees C, space velocity 2000 h(-1) and the feed of 20% C3H6/8% O-2/N-2, 4% conversion of propylene and 46.8% selectivity to propylene oxide were obtained over the 20 wt% Ag-0.1% Y2O3-0.1% K2O/alpha-Al2O3 catalyst.

• 出版日期2007-10-17
• 单位华东理工大学