| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas cleaning catalyst the deterioration of which can be judged with high precision by approaching the judged result based on oxygen concentration, which can be measured while riding in a car as a method for easily evaluating the performance of the exhaust gas cleaning catalyst, to the judged result based on light-off temperature (T50). <P>SOLUTION: The exhaust gas cleaning catalyst containing an oxygen storage material particle being an oxygen storage material particle mixture obtained by mixing a first cerium-based oxygen storage material particle (A) having a first number-average particle diameter with a second cerium-based oxygen storage material particle (B), which has the same composition as that of the first cerium-based oxygen storage material particle (A) and a second number-average particle diameter larger than the first number-average particle diameter, so that the time that the oxygen storage/release capacity of the exhaust gas cleaning catalyst is deteriorated becomes a predetermined time. <P>COPYRIGHT: (C)2008,JPO&INPIT |
