| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of excellently purifying NOx in inflow exhaust gas, even when the temperature of a NOx catalyst is lower than the NO oxidation starting temperature. <P>SOLUTION: This exhaust emission control device is provided with a NOx storage means for carrying a NOx occlusion agent 55 and a noble metal catalyst 54 in an engine exhaust passage. The NOx occlusion agent performs the NOx occlusion-emission action when the temperature of the noble metal catalyst is the NO oxidation starting temperature or more. A NOx occlusion means has a small quantity carrying area 56 and a large quantity carrying area 57. A carrying quantity of the noble metal catalyst per unit volume in the small quantity carrying area, is less than a carrying quantity of the noble metal catalyst per unit volume in the large quantity carrying area. The small quantity carrying area and the large quantity carrying area are arranged so that exhaust gas flowing in the NOx occlusion means, passes through the large quantity carrying area after passing through the small quantity carrying area. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
