Structure peculiarities of reduced vanadium-titanium oxide catalysts

The properties of vanadium-titanium oxide catalysts, which contain coherent phase boundaries formed by V2O5 and TiO2 crystallites during reduction by hydrogen at 150-500 degreesC, are examined. The phase boundary is preserved over the entire examined temperature range regardless of the structure of vanadium oxide, which is formed. The state of vanadium ions at the phase bo undary is determined. The presence of a phase boundary in the catalyst is r esponsible for the V2O5 --> V2O3 transition without the formation of interm ediate structures.