| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method which allows precise detection of degradation of an exhaust gas purification catalyst even when a noble metal exhaust gas purification catalyst is used. <P>SOLUTION: The degradation detecting method includes forced rich control, the detection of oxygen release amount in the forced rich control, forced lean control, the detection of oxygen absorption amount in the forced lean control and the calculation of oxygen storage ability of the exhaust gas purification catalyst. The degradation detecting method further includes: setting the content of the noble metal catalyst in the exhaust gas purification catalyst to ≤2 g per 1L exhaust gas purification catalyst; using a barium compound as an additive to a support containing an OSC material; controlling the air/fuel ratio of a gaseous mixture in the forced rich control to A/F<14.7; controlling the air/fuel ratio of the gaseous mixture in the forced lean control to A/F=14.7±0.05; and performing the degradation determination of the exhaust gas purification catalyst on the basis of the calculated oxygen storage ability. <P>COPYRIGHT: (C)2013,JPO&INPIT |
