Immobilized Vanadium Compounds within Nanoreactors of Al-MCM-41 as Catalyst for Epoxidation of Alkenes

VO2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of Al-MCM-41 designated as VO2+/Al-MCM-41 or VOL2/Al-MCM-41, were prepared and characterized by X-ray powder diffraction (XRD), FT-IR, BET nitrogen adsorption-desorption and chemical analysis techniques. VO2+/Al-MCM-41 and VOL2/Al-MCM-41 were found to catalyze the epoxidation of trans-stilbene, norbornene, and geraniol with aqueous hydrogen peroxide (H2O2) in refluxing acetonitrile with 30-80% conversion and up to 98% selectivity toward the formation of the corresponding epoxides. On the other hand, under similar conditions, these alkenes underwent epoxidation with 50 to 99% conversion and up to 100 % selectivitiy in the presence of VO(acac)2/Al-MCM-41with tert-butylhydroperoxide (TBHP) as oxidant.