Catalytic epoxidation of cyclohexene over mesoporous-silica immobilized Keggin-type tungstophosphoric acid

A series of aminosilylated mesoporous silica (SBA-15) samples with different contents of (3-aminopropyl)triethoxysilane (APTES), synthesized using a simple one-pot method, were used as hosts for immobilization of Keggin-type 12-phosphotungstic acid (H3PW12O40). The loading of H3PW12O40 increased with increasing content of grafted APTES. The obtained materials were calcined at different temperatures, and the tungsten species were highly dispersed inside the SBA-15 channels. The catalytic activities of these samples were tested in heterogeneous oxidation of cyclohexene using H2O2. as the oxidant. The effects of different loadings and treatment temperatures on the activities of the catalysts were also investigated. The catalysts calcined at 400 degrees C showed high catalytic activities and reusabilities. (C) 2013, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.