V₂O₅-V₂O₃ TRANSITION IN VANADIUM-TITANIUM OXIDE CATALYST

D.O.Klenov¹, G.N.Kryukova², S.V.Tsybulya², G.A.Zenkovets²

¹Novosibirsk State University, Pirogova 2a, Novosibirsk, 630090 Russia
²Boreskov Institute of Catalysis, Lavrentieva 5, Novosibirsk, 630090 Russia E-mail: Dmitrij.Klenov@cclib.nsu.ru

Keywords: V₂O₅, V₂O₃, TiO₂(anatase), reduction, interface

Using high resolution electron microscopy and X-ray powder diffraction structural behaviours of TiO₂(anatase) catalyst with 20% loading of V₂O₅ upon reduction conditions was investigated. Temperatures of reduction were in the range from 150 to 500^oC. Change of the crystalline properties of vanadium oxide in the V₂O₅/TiO₂(anatase) catalyst at the reduction process was discovered. Amorfisation and disappearance of V₂O₅ and its transformation into V₂O₃ was observed. Transformation of V₂O₅ to V₂O₃ occurred without formation of the intermediate structures. This behaviours of vanadium oxide in the catalyst differ from that of pure vanadium oxide upon reduction as well as those of mechanical mixture of vanadium oxide and anatase. Reduction of pure V₂O₅ goes through formation of intermediate structures of homological sequence such as V_nO_2n+-1. Such properties are explained as the result of the interaction between vanadium and titanium oxides with formation of the interface.