FORMATION OF CEVO4 PHASE DURING THE PREPARATION OF CUVCE OXIDE CATALYSTS

The presence of copper and vanadium in ceria at different concentratio ns gives solids with different characteristics which vary with calcina tion temperature. At low copper and vanadium concentrations, only the CeO2 phase is formed. When the concentration of copper is relatively h igh compared to vanadinmm a CuO phase appears alongside CeO2. However, when the concentration of vanadium is relatively high compared to cop per, CeVO4 and V2O5 phases are formed along with CeO2. The formation o f the CeVO4 phase is due to the reaction between a trapped electron an d V2O5-x/CeO2-y leading to reduction of Ce-IV to Ce-III.