| 摘要 |
PROBLEM TO BE SOLVED: To improve the NOx purifying performance in a lean atmosphere for which a sufficient activity is not exhibited by the conventional catalyst and to allow the catalyst to function sufficiently as a ternary catalyst. SOLUTION: A platinum-on-zeolite first catalyst is arranged in the preceding stage with respect to the exhaust gas flow in this exhaust gas purifying catalyst. A second catalyst contg. alumina carrying each of at least one kind selected from a group consisting of platinum. palladium, rhodium and iridium and a multiple oxide shown by (La1-x Ax )1-α BO1-δ (0<x<1, 0<α<0.2, 0<=δ<=1, A is barium and/or potassium, and B is at least one kind selected from a group consisting of iron, cobalt, nickel and manganese) is arranged in the subsequent stage. |
