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

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.