Effect of vanadia and tungsten loadings on the physical and chemical characteristics of V2O5-WO3/TiO2 catalysts

Abstract Titania-supported tungsten and vanadia oxides with different W and V loadings and calcined at different temperatures have been prepared by the sol–gel method and characterized. Large amount of tungsten (9%; w/w) provides thermal stability to WO 3 /TiO 2 systems upon addition of vanadia. It is found that WO 3 and V 2 O 5 crystallites are formed when their concentrations are higher than those corresponding to three monolayers. DTA analyses have shown that the presence of V 2 O 5 crystallites is not essential for the transformation of titania anatase into rutile. High reactivity in limited temperature range (225–350 °C) has been observed for the catalyst with 8% (w/w) V 2 O 5 with a high formation of N 2 O amount during the SCR reaction. The catalyst with 3% (w/w) V 2 O 5 exhibits a slight lower reactivity but with a high selectivity to N 2 preserved in all working temperature.