| 摘要 |
PROBLEM TO BE SOLVED: To provide a cerium-zirconium type complex oxide which has excellent OSC and a high catalytic activity and is also excellent in heat resistance and a production method of the cerium-zirconium type complex oxide.SOLUTION: A cerium-zirconium type complex oxide comprises cerium, zirconium, and platinum group metals. After 3-h heat treatment at 1,000-1,100°C, (1) its crystal structure contains a pyrochlore phase; (2) it has a value of {I111/(I111+I222)}×100 of 1 or greater, with the peak intensity of the (111) plane taken as I111 and the peak intensity of the (222) plane as I222, measured in the plane in parallel with the lengthwise direction of the crystal structure by the X-ray diffraction method; and (3) it has an oxygen absorption/emission capacity at 450°C of 0.10 mmol/g or higher. |
