文献类型：期刊文献

英文题名：Study of Higher Selectivity to Styrene Oxide in the Epoxidation of Styrene with Hydrogen Peroxide over La-Doped MCM-48 Catalyst

作者：Zhan, Wangcheng[1];Guo, Yanglong[1];Wang, Yanqin[1];Guo, Yun[1];Liu, Xiaohui[1];Wang, Yunsong[1];Zhang, Zhigang[1];Lu, Guanzhong[1]

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2009

卷号：113

期号：17

起止页码：7181

外文期刊名：JOURNAL OF PHYSICAL CHEMISTRY C

收录：;EI(收录号：20092512139453);WOS:【SCI-EXPANDED(收录号:WOS:000265529700046)】；

基金：This project was financially supported by National Basic Research Program of China (2004CB719500), International Science and Technology Cooperation Program of China (2006DFA42740), and Commission of Education of Shanghai Municipality (2008CG35).

语种：英文

外文关键词：Styrene - Molecular sieves - pH - Sodium hydroxide - Catalyst selectivity - Hydrogen peroxide - Lanthanum compounds

摘要：The epoxidation of styrene with hydrogen peroxide with higher selectivity to styrene oxide was carried out over lanthanum-doped MCM-48 (La-MCM-48) molecular sieves, in which aqueous NaOH solution was used to adjust the pH value of the reaction solution. The results show that the pH value of the reaction solution has a great influence on the catalytic performance of La-MCM-48 and the product distribution. When the pH value of the reaction solution was 11.5, the conversion of styrene reached 54.5% and the selectivity to styrene oxide was 98.8%. UV-vis and EPR spectroscopy was used to characterize the lanthanum species in the framework of La-MCM-48 and the peroxo-lanthanum species by H2O2 reacting with the lanthanum species. It has been found that the conversion of styrene has a close relationship with the amount of the peroxolanthanum species, and the selectivity to styrene oxide has a close relationship with the ratio of La(III)-superoxide species to La(III)-hydroperoxide species, which can be controlled by adjusting the pH value of the reaction solution.