文献类型：期刊文献

英文题名：A Ti-substituted polyoxometalate as a heterogeneous catalyst for olefin epoxidation with aqueous hydrogen peroxide

作者：Hua, Li[1];Qiao, Yunxiang[1];Yu, Yinyin[1];Zhu, Wenwen[1];Cao, Ting[1];Shi, Yu[1];Li, Huan[1];Feng, Bo[1];Hou, Zhenshan[1]

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

年份：2011

卷号：35

期号：9

起止页码：1836

外文期刊名：NEW JOURNAL OF CHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000294263700010)】；

基金：The authors are grateful for the support from the National Natural Science Foundation of China (No. 20773037, No. 21073058), and Research Fund for the Doctoral Program of Higher Education of China (20100074110014). The authors would also like to express their thanks to Prof. Walter Leitner for helpful suggestion and Dr Nils Theyssen for assistance.

语种：英文

摘要：The Ti-substituted polyoxometalates ([C(12)mim](5)PTiW11O40, [CTA](5)PTiW11O40 and [TBA](5)PTiW11O40) were prepared and characterized by FT-IR, NMR, UV-vis and ICP-AES. Then the polyoxometalates (POM) were used as catalysts for the epoxidation of various olefins. It was found that the organic countercations had a considerable effect on the catalytic performance. In addition, UV-vis and the FT-IR spectroscopy indicated that the peroxo structure regarded as the active site for oxygen transfer was present even after the reaction, which led to the increasing reaction rate in the second run due to the disappearance of the induction period, as compared with that in the first run. A heterogeneous reaction mechanism has been suggested in olefin epoxidation catalyzed by a Ti-substituted polyoxometalate ([C(12)mim](5)PTiW11O40) with aqueous hydrogen peroxide in ethyl acetate. The heterogeneous POM catalyst can be easily separated and recycled eight times without decreasing the catalytic activities.