| 摘要 |
PROBLEM TO BE SOLVED: To further improve activity at a low temperature and durability of a catalyst having a carrier containing cerium oxide. SOLUTION: The carrier is formed from an Al-Ce-Zr-Pr complex oxide obtained by compositing oxides of Al, Ce, Zr and Pr, and at least one of noble metals is supported on the carrier. Addition of the oxide of Pr makes the balance between acidity and basicity of the complex oxide optimum, and thereby it is considered that the absorbance of HC or the like becomes optimum and further, the activity at a low temperatures is improved and the catalyst exhibits high oxygen absorbing and desorbing abilities and a high specific surface area even after it is used for a long period of time. |
