| abstract |
An exhaust gas purify catalyst includes a substrate ( 1 ), an oxidation catalyst layer ( 2 ) formed on the substrate ( 1 ) and containing zeolite and at least one catalytic metal, an LNT layer ( 3 ) formed on the oxidation catalyst layer ( 2 ) and containing an NO x storage material and at least one catalytic metal, and an NO x reduction layer ( 4 ) formed on the LNT layer ( 3 ) and containing Rh acting as a catalytic metal and at least one of alumina or zirconia, wherein the NO x reduction layer ( 4 ) has a larger content of Rh than that in each of the oxidation catalyst layer ( 2 ) and the LNT layer ( 3 ). |