| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a catalyst apparatus for cleaning an exhaust gas, which exhibits both NOx trap performance and ternary catalyst performance and has improved exhaust gas cleaning efficiency, without causing a decrease in engine power due to an increase in loss of exhaust gas pressure. <P>SOLUTION: This catalyst apparatus comprises a carrier 32 with a through-hole 31 arranged in an exhaust gas channel Re and penetrating in the axial direction (f) (the passage direction), and a carrier layer 33 consisting of fireproof inorganic oxides on the internal surface of the through-hole 31. The carrier layer carries a noble metal 34, and a NOx trap agent which occludes NOx in the exhaust gas when a exhaust air-fuel ratio is lean and discharges the occluded NOx for reduction treatment when the exhaust air-fuel ratio is at a theoretical air-fuel ratio or rich. The amount of the carried noble metal 34 in the upstream area of the exhaust gas channel of the carrier is set smaller than that in the downstream area of the exhaust gas channel. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
