Some Physico-chemical Properties of Vanadium Oxide Supported on Silica or γ-Alumina

Abstract

The interactions between vanadium(V) oxide and carriers were investigated in the vanadium oxide catalysts supported on silica and γ-alumina by measuring X-ray diffraction patterns, ESR spectra, solubilities into 0.3 n ammoniacal solutions and reduction rates by benzene. A part of vanadium oxide on the carriers was insoluble in an ammoniacal solution, while unsupported vanadium oxide was easily soluble, and the reduction rates of the catalysts were remarkably affected by the carriers and the vanadium oxide contents. ESR spectra revealed that the vanadium oxide was stabilized by interaction with carriers as a square pyramidal one (VO5) and a tetrahedral one (VO4) on the surfaces of γ-alumina and silica, respectively. Massive vanadium(V) oxide crystals grew on these interacted layers with the increase of the oxide contents.