Vanadia and tungsta grafted on TiO2: influence of the grafting sequence on structural and chemical properties Original Research Article

Ternary V2O5–WO3/TiO2 catalysts were prepared by sequential or simultaneous grafting steps of vanadia and tungsta onto titania and were compared with similarly prepared binary catalysts. Different grafting sequences including alternating grafting of vanadia and tungsta were compared. During the grafting process the metal oxide precursor reacted with hydroxyl groups of the other grafted metal oxide. The interaction of vanadia with tungsta species resulted in a different reduction behavior of both metal oxides compared to the binary catalysts as indicated by temperature-programmed reduction with hydrogen. The strength of interaction of the grafted species depended on preparation sequence and metal loading. At low coverage (