| abstract |
(57) Abstract: also can improve the NO x purification performance in the low temperature region and a low HC / NO x ratio failed to show a sufficient purification ability in conventional catalysts, and high temperature water Provided are an exhaust gas purifying catalyst and an exhaust gas purifying method capable of suppressing catalyst deterioration even under thermal conditions. SOLUTION: An exhaust gas purifying catalyst is platinum (Pt), A first component comprising at least one component selected from the group consisting of palladium (Pd) and rhodium (Rh) and one or more components selected from the group consisting of alkali metals, alkaline earth metals and rare earth metals; A catalyst layer, a second catalyst layer containing β zeolite containing a copper (Cu) and / or cobalt (Co) component, and an MF containing a copper and / or cobalt component A third catalyst layer containing I zeolite, wherein the second catalyst layer is provided on the first catalyst layer, and the third catalyst layer is provided on the second catalyst layer. Preferably, such an exhaust gas purifying catalyst has an air-fuel ratio of exhaust gas of 14.7 or more and an oxygen concentration of 5%. The above is used for an internal combustion engine having an HC / NO x ratio of more than 0 and 10 or less. |