Synthesis of Highly Dispersed Co-MCM-41 by a Novel Two-Step Method and Its Catalytic Performance in Aerobic Epoxidation of Styrene

In the present study, highly dispersed Co-MCM-41 catalysts have been prepared by a novel two-step method consisting of the co-condensation and the template ion exchange. The samples are characterized by ICP–AES, UV-vis, N2-adsorption and XRD, respectively, and evaluated by the epoxidation of styrene using molecular oxygen as oxidant. The typical samples have the pore structure and phase characteristics of MCM-41 mesoporous molecular sieve. Introducing methyl or ethyl into MCM-41 can really increase the Co dispersity of the final Co-MCM-41 and accordingly improve its catalytic performance. Higher Co dosages will give rise to higher Co/Si in final catalysts and better catalytic performance to an appropriate extent. Among the catalysts, the sample with a dosage of 0.05 methyl/Si and a dosage of Co/Si of 0.02 performs best in catalytic epoxidation of styrene. The sample results in a highest Yield of styrene oxide of 29.0% and can be used 3 times in the reusing test.