Enhancing Isolated Ti(Ⅳ) Framework Sites in HMS  

作　　者：YU Wei-hua ZHOU Chun-hui NI Zhe-ming GE Zhong-hua 

机构地区：[1]College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310024, P. R. China

出　　处：《Chemical Research in Chinese Universities》2007年第2期127-130,共4页高等学校化学研究（英文版）

基　　金：the National Natural Science Foundation of China(No 20541002);the Natural Science Foundation of Zhejiang Province(No 405025)

摘　　要：Ti-HMS materials were prepared by grafting titanocene onto the inner wails of hexagonal mesoporous silica （HMS）. The materials were characterized via powder X-ray diffraction, N2 adsorption-desorption isotherms, diffuse reflectance UV-Vis spectroscopy, and thermo-gravimetric analysis. The template of HMS was removed by calcination, ethanol-extraction, and ethanol-extraction followed by hydrolysis. The available grafting sites of OH groups depend on the different template removal methods of HMS. Ethanol-extraction followed by hydrolysis favors site-isolated Ti atoms in HMS. The catalytic performances of Ti-HMS materials were tested in the oxidation of 4-tert-butyholuene with aqueous hydrogen peroxide. Ti-HMS prepared from HMS via the processing of ethanol-extraction followed by hydrolysis as support gave a maximum conversion of 7. 5% and a complete selectivity to 4-tert-butyl-benzaldehyde, and showed a higher activity compared with those prepared by calcination and ethanol-extraction.Ti-HMS materials were prepared by grafting titanocene onto the inner wails of hexagonal mesoporous silica （HMS）. The materials were characterized via powder X-ray diffraction, N2 adsorption-desorption isotherms, diffuse reflectance UV-Vis spectroscopy, and thermo-gravimetric analysis. The template of HMS was removed by calcination, ethanol-extraction, and ethanol-extraction followed by hydrolysis. The available grafting sites of OH groups depend on the different template removal methods of HMS. Ethanol-extraction followed by hydrolysis favors site-isolated Ti atoms in HMS. The catalytic performances of Ti-HMS materials were tested in the oxidation of 4-tert-butyholuene with aqueous hydrogen peroxide. Ti-HMS prepared from HMS via the processing of ethanol-extraction followed by hydrolysis as support gave a maximum conversion of 7. 5% and a complete selectivity to 4-tert-butyl-benzaldehyde, and showed a higher activity compared with those prepared by calcination and ethanol-extraction.

关 键 词：TI-HMS GRAFTING Oxidation 4-tert-Butyltoluene 

分 类 号：TQ424.25[化学工程]