Effect of WO3 in mixed V2O5–WO3/ZrO2 catalysts on their surface structures and decomposition of propan-2-ol

Abstract

V₂O₅–WO₃/ZrO₂ catalysts prepared by a two-step impregnation method have been studied by FTIR and laser-Raman spectrometry together with a pulse method. Addition of WO₃ to 2 wt.% V₂O₅/ZrO₂ catalyst increased the activity of propan-2-ol decomposition and the selectivity for propene. On 5 wt.% V₂O₅/ZrO₂ catalyst the activity was hardly affected but the selectivity for propene was increased by the additive. From the FTIR bands in the region of 1100–900 cm^-1, when WO₃ was added to V₂O₅/ZrO₂ catalysts, the tungsten oxide species was well dispersed on the zirconia support and directly interacted with zirconia to form the bridging layer(s) between the support and vanadate species. Thus, the addition of WO₃ caused the reconstruction of the surface vanadate species. As a result, the surface acidity as well as the catalytic activity changed with the amount of WO₃.