Effect of support and prfparation on structure of vanadium oxide catalysts

Supported vanadium oxides were prepared by both the conventional impregnation and vapour-phase-supporting methods; TiO₂(anatase), TiO₂(rutile), TiO₂(mixture of anatase with rutile), Al₂O₃, ZrO₂, SiO₂, and MgO were used as supports. The structure of the catalyst was characterized by using the rectangular pulse technique coupled with various physico-chemical measurements. It was found that the structure of the vapour-phase-supported V₂O₅/Al₂O₃, catalyst does not change significantly from that of the V₂O₅/Al₂O₃ prepared by the conventional impregnation method. The (010) face of V₂O₅ was found to grow epitaxially on the TiO₂ support, irrespective of the modification of TiO₂. It was also found that the structures of V₂O₅/TiO₂, V₂O₅/Al₂O₃, V₂O₅/ZrO₂, V₂O₅/SiO₂, and V₂O₅/MgO differ greatly from one another. From these results, it was concluded that the structure of vanadium oxide on support is mainly determined by the kind of support, while neither the method of preparation nor the modification of the support affects the structure significantly.