Direct Oxidation of Benzene to Phenol by Dioxygen over Nano-vanadium Oxide

Abstract

Reducing regents, such as ascorbic acid, are needed for vanadium-containing catalysts to catalyze the direct oxidation of benzene to phenol by dioxygen. Quadrivalent vanadium species, reduced from quinquevalent vanadium species, can activate dioxy.-en to produce active oxygen species. which is important for the reaction The key step is to prepare more V-44-containing catalysts Here, VOx-C16-A was prepared in in acidic medium to produce more V4+ species. The results of XPS and XRD studies confirmed that the vanadium species in VOx-C-16-(A) was mainly V4+ ions The results of XRD and electron diffraction patterns revealed that VOx-C-16-A consisted of tetragonal VO2 and monoclinic VO2, Morphology observations display that the VOx-C-16-(A) is made of nanorod. Investigations into the performances of the catalysts showed that VOx-C-16-(A) was reusable, producing a 1.9% conversion of benzene without reducing agent