Thermal reduction of vanadium pentoxide: an XPD study
1999; Elsevier BV; Volume: 433-435; Linguagem: Inglês
10.1016/s0039-6028(99)00171-5
ISSN1879-2758
AutoresK. Devriendt, H. Poelman, L. Fiermans,
Tópico(s)Catalysis and Oxidation Reactions
ResumoTransition metal oxide surfaces are of interest for a number of catalytic phenomena. In the framework of a V2O5/TiO2 catalyst project, the reduction of V2O5 to lower oxides is investigated by means of X-ray photoelectron diffraction (XPD). Cleaved V2O5(001) surfaces, previously characterized by means of XPD in combination with single scattering simulations, were now reduced by heating (500°C) under an O2 atmosphere (5×10−4 Torr, 1 h). XPD intensity patterns were recorded with a laboratory XPS apparatus equipped with an Al Kα source (V 2p3/2, Ek=960 eV), as well as at the LURE synchrotron radiation facility (V 3p3/2, Ek=68 eV). Single scattering simulations were performed for V2O5(001), oxygen deficient V2O5(001) and V6O13(001) structures. V6O13 is a shear structure of V2O5 and alternates double and single VO-layers. It is seen that the simulations for the single crystal V6O13 reproduce the experimental XPD patterns best. Moreover, the results point towards a termination of the V6O13(001) structure, where the double VO-layer is at the top.
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