Heterogenized Molybdovanadophosphoric Acid on Amine-Functionalized SBA-15 for Selective Oxidation of Alkenes

Abstract

Mono-vanadium substituted molybdovanadophosphoric acid has been immobilized on amine-functionalized SBA-15 and characterized by different techniques. Small angle X-ray scattering (SAXS) analysis and SEM technique provide evidence for the structural integrity of the amine-functionalized SBA-15 and for the molybdovanadophosphoric acid immobilized sample. Diffuse reflectance UV–vis, 31P, 51V-NMR and FT-IR data confirm the incorporation of molybdovanadophosphoric acid onto the amine-functionalized SBA-15. The textural properties of these materials were studied by nitrogen sorption studies. Oxidation of selected substrates, norbornene, cyclooctene, cyclohexene and styrene with aqueous hydrogen peroxide was carried out with the immobilized molybdovanadophosphoric acid catalyst (heterogenized) and the results were compared with that of the neat molybdovanadophosphoric acid catalyst (homogeneous). The selectivity of the desired products was higher with the immobilized catalyst. The immobilized catalyst could be separated after the reaction and the reusability of the catalyst has also been demonstrated.