Unexpected mononuclear W(VI) complexes containing phosphonate ligands anchored on mesoporous silica. Another strategy for immobilization

Tungsten species have been immobilized onto the surface of mesoporous silica SBA-15 modified by diethylphosphatoethyltriethoxysilane. As a result, a novel tungsten catalyst named HPWX-SBA has been prepared. The physicochemical properties of this novel catalyst have been studied through various characterization methods such as ICP, FT-IR, Raman and 31P NMR. The fine structure of the tungsten species on the surface of HPWX-SBA has been proposed. It is found that HPWX-SBA shows high conversion and selectivity in the selective oxidation of cyclopentene to produce glutaraldehyde using H2O2 as oxidant and can preserve high activity after several cycles of reaction.