Zinc polyoxometalate immobilized on ionic liquid-modified MCM-41: an efficient reusable catalyst for the selective oxidation of alcohols with hydrogen peroxide

摘要

In this study, Keggin-type polyoxometalate [n-C4H9)(4)N](x)[PW11ZnO39].nH(2)O was successfully immobilized on imidazole-functionalized ionic liquid-modified mesoporous MCM-41 by physical adsorption. The PW11Zn@MCM-41-Im was characterized by FT-IR, ICP, XRD, SEM, nitrogen adsorption and desorption and DRUV-Vis analysis. The results indicated that ZnPW11 could be successfully immobilized on mesoporous MCM-41-Im. This heterogeneous catalyst showed high catalytic performance and excellent selectivity in the oxidation of alcohols to the corresponding carbonyl groups with hydrogen peroxide. Furthermore, the supported ionic liquid catalyst was recovered by simple filtration and reused in four reaction runs with the preserve of the catalytic activity.