Effects of V2O5 and WO3 loadings on the catalytic performance of V2O5-WO3/TiO2 catalyst for SCR of NO with NH3

Abstract

V2O5-WO3/TiO2 catalysts were fabricated by a simple impregnation method. Effects of V2O5 and WO3 loadings on the catalytic performance of V2O5-WO3/TiO2 catalyst for selective catalytic reduction (SCR) of NO with NH3 were investigated. Morphology and structure of the V2O5-WO3/TiO2 catalysts were characterised by XRD, SEM, XPS, and N2 adsorption techniques. The XRD patterns of the V2O5-WO3/TiO2 catalyst are indexed to anatase-TiO2. XPS spectra analysis confirms that V, Ti, W and O species exist on the surface of V2O5-WO3/TiO2 catalyst. V2O5 species are the main active sites in the process of SCR reaction. Increasing V2O5 loading in the V2O5-WO3/TiO2 catalysts can improve their catalytic performance. Exceeding 2 wt%, the catalytic performance of V2O5-WO3/TiO2 catalyst begins to decline because high V2O5 loading on TiO2 speeds up the growth of anatase grains, which leads to the loss of catalytic activity. Appropriate WO3 species can significantly improve the catalytic performance of V2O5-WO3/TiO2 catalysts. However, as the WO3 loadings reaches 6 wt%, NO conversion decreases instead.