Preparation of mixed oxide powders in the system CeO2-ZrO2-MOx (M = transition and rare earth metals) by coprecipitation method for the purification catalysts of automotive emission

Abstract

Powders in the CeO2-ZrO2-MOx system were prepared by coprecipitation method. Influence of adding a third components MOx of transition metal oxides and rare earth metal oxides on the specific surface area (SA) and oxygen storage capacity (OSC) were investigated. It was found that transition metal oxides decrease drastically both SA and OSC values at 1000°C. On the other hand, rare earth metal oxides slightly decreased OSC values. The OSC values of the 20CeO2-(80-y)ZrO2-yMOx powders with y=0-20 mol% LaO1.5, showed a maximum at around 6 mol% LaO1.5. In the CeO2-ZrO2-MOx system, 20CeO2 · 74ZrO2 · 6LaO1.5 (mol%) powders exhibited the most efficient performance with a high thermal stability up to 1000°C.