ANGULAR RESOLVED XPS APPLIED TO V2O5-BASED CATALYSTS

Two applications of angular dependent XPS (X-ray photoelectron spectro scopy) experiments, performed with a Perkin Elmer Phi 5500 ESCA system in the framework of a monolayer catalyst research project, are illust rated. XPFS (X-ray photoelectron forward scattering) measurements were used to show the oxygen removal at the surface of catalytically reduc ed V2O5(001) pellets, in comparison with pure V2O5. ARXPS (angle resol ved XPS) polar scans were taken from a model catalyst system (TiO2 ana tase supported V2O5 layers) in order to determine their components and the chemical state of the system. With the use of the statistical tec hnique MLCFA (maximum likelihood common factor analysis), different ov erlapping components in the V and Ti photoemission peaks were separate d, pointing towards the existence of a V-Ti-O bonding at the V2O5/TIO2 interface.