| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas treatment catalyst capable of keeping a stable and high NO<SB>x</SB>treatment capability for a long period of time by suppressing deterioration on the upstream part of the catalyst to the exhaust gas. <P>SOLUTION: The exhaust gas treatment catalyst is an exhaust gas treatment catalyst for treating hydrocarbons, carbon monoxide, and nitrogen oxide in exhaust gas in excess oxygen atmosphere and consisting of a porous carrier and an NOx-storage material containing Pd and at least one of Pt and Rh and deposited on the porous carrier. Palladium is deposited in the upstream part of the porous body in the exhaust gas flow direction. Pd is desirable to be deposited in a high concentration in a range of at least 20 mm from the end face of the porous carrier in the exhaust gas flow-in side. <P>COPYRIGHT: (C)2009,JPO&INPIT |
