| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas treatment catalyst which can exhibit an NOx adsorption function, an NOx desorption function, and an NOx reduction removal function in good balance at a low cost and an exhaust gas treatment method using the catalyst. <P>SOLUTION: The exhaust gas treatment catalyst is composed of an upstream side catalyst part and a downstream side catalyst part and the upstream side catalyst part and the downstream side catalyst part contain a catalytic noble metal and an NOx adsorption catalyst and the ratio of the total mole amount of the NOx adsorption catalyst on the basis of an oxide to the total mole amount of the catalytic noble metal in the upstream side catalyst part is smaller than that of the downstream side catalyst part. The exhaust gas treatment system use the exhaust gas treatment catalyst and has 350°C or higher inlet temperature of the upstream side catalyst part. <P>COPYRIGHT: (C)2003,JPO |
