Preparation, characterization and testing of newly developed titania supported VPO catalysts Original Research Article

Titania-supported vanadium-phosphorus oxide catalysts were prepared via deposition-precipitation from a homogeneous solution of lower valent vanadium ions in combination with phosphate-ions onto titania support bodies. From the results of different characterization techniques, it was concluded that the precipitated vanadium-phosphorus oxide phase was amorphous and that it was very well dispersed over the surface of the support. Also, it was found that the active phase exhibited a very strong interaction with the titania support. The prepared catalysts already showed activity at remarkably lower temperatures than industrially utilized catalysts. However, the selectivity at high conversions was small. The performance of the catalyst was found to be related to the reducibility of the active phase. For this system, an enhanced reducibility was detected due to the strong interaction of the active phase with the titania support, which was proved to be a function of the vanadium loading. The activity and selectivity in the oxidation of n-butane were only slightly affected by the installed PV ratio.