Formation of CeVO4phase during the preparation of CuVCe oxide catalysts

Abstract

The presence of copper and vanadium in ceria at different concentrations gives solids with different characteristics which vary with calcination temperature. At low copper and vanadium concentrations, only the CeO₂ phase is formed. When the concentration of copper is relatively high compared to vanadium, a CuO phase appears alongside CeO₂. However, when the concentration of vanadium is relatively high compared to copper, CeVO₄ and V₂O₅ phases are formed along with CeO₂. The formation of the CeVO₄ phase is due to the reaction between a trapped electron and V₂O_5−x/CeO_2−y leading to reduction of Ce^IV to Ce^III.