| abstract |
An exhaust emission control catalyse which is capable of exhibiting an excellent NO x converting ability in an excessive-oxygen atmosphere even after being exposed to a high-temperature environment including oxygen and water vapor. The catalyst contains a crystalline aluminosilicate with a catalytic metal carried thereon and CeO 2 as the basic forming components. The crystalline aluminosilicate has at least one of Mg, Ca, Sr, Ba, Ti, v, Fe, Zn, Ga, Y, Zr, Mo, In, La, Ce, Nd, Ir, Pb and Sn carried thereon. The catalytic metal exhibits an oxidizing ability and a reducing ability to an exhaust gas. The crystalline aluminosilicate has a function of adsorbing HC to concentrate it and to supply such HC to the catalytic metal. Each of Mg, Ca, Sr, and Ba has a function of maintaining the function of the crystalline aluminosilicate, and each of the other metal elements has a function of maintaining the function of the catalytic metal. |