ChemInform Abstract: Structure and Acidity of Vanadium Oxide Layered on Titania (Anatase and Rutile).

Abstract

Structure and Acidity of Vanadium Oxide Layered on Titania (Anatase and Rutile).-The influence of the crystalline phase of TiO2 on the acidic properties and the nature of vanadia species is investigated by using FTIR and laser Raman spectroscopies. The vanadium oxide layers (1.2-3. 4 wt.%) are deposited by reaction of VOCl3 vapor with the surface hydroxyl groups of the support. The IR spectra for pyridine adsorbed on the V-Ti oxide show both Broensted and Lewis sites to be present. Increasing vanadium loadings result in an increase of Broensted sites on both catalyst series (anatase, rutile). The catalysts of the anatase series exhibit higher concentrations of Lewis sites. The vanadium oxides on both series are composed mainly of surface V2O5 species, which resist heat treatment at 673 K. The reactivity of the V= O bond of the rutile catalyst differs from that of anatase. -(HATAYAMA, F.; OHNO, T.; MARUOKA, T.; ONO, T.; MIYATA, H.; J. Chem. Soc., Faraday