COMPOSITE OXIDE POWDER, METHOD OF PRODUCING THE SAME AND CATALYST THEREFOR

摘要

PROBLEM TO BE SOLVED: To improve gas diffusion property and oxygen occluding/releasing function when used as a catalyst. SOLUTION: The composite oxide powder comprises a composite oxide of CeO2-ZrO2 solid solution and a metal M oxide which are insoluble into each other, and has at least two pore distributions in the region of <=500 nm. The catalyst comprises the composite oxide powder which carries a precious metal, and has the precious metal which is highly dispersed into a pore in a first pore distribution in a 3.5-50 nm region, and thus improves cleaning activity and oxygen occluding/releasing function and also improves gas diffusion property owing to a second pore distribution in a 50-500 nm region.