The Fabrication of PMo11Fe Cluster Supporting on SBA-15 and Catalytic Epoxidation of Cyclooctene with H2O2 as Oxidant

The transition metal iron substituted polyoxometalates cluster (PMo11Fe) was immobilized on NH2 functionalized SBA-15 with the post-modified method, the resulting composite materials, abbreviated as PMo11Fe/SBA. Multiple characteristic methods including X-ray powder diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the composite PMo11Fe/SBA, it is concluded that PMo11Fe cluster was supported on the NH2 functionalized SBA-15, and the Keggin structure of PMo11Fe cluster kept retained during the immobilized process. The cyclooctene epoxidation results with H2O2 as the oxidant demonstrated that PMo11Fe/SBA performed better catalytic activities and recyclability, the conversion of cyclooctene kept about 50% after several recycled reactions. The superior recyclability of PMo11Fe/SBA could be attributed to the multiple electrostatic and coordinative interactions between PMo11Fe clusters and functionalities -NH2 located at the 3D pore wall of SBA-15. Besides, the catalytic activities and stability could be improved through the partial substitute of transition metal Fe instead of Mo atom in phosphomolybdic acids clusters.