| 摘要 |
PURPOSE:To obtain an exhaust gas purifying catalyst having high oxidizing activity to harmful components in exhaust gas from an internal combustion engine of a car in a low temp. region and capable of reducing cold HC discharged immediately after the start of an engine. CONSTITUTION:An exhaust gas purifying catalyst is composed of multicomponent composite oxide containing palladium, iron and cerium represented by general formula PdaFebCecXdYeOf (X is at least one kind of an element selected from the group consisting of potassium, rubidium, cesium and barrium, Y is at least one kind of an element selected from the group consisting of copper, magnesium, zinc, germanium, silicon, nickel, silver, chromium, lanthanum, strontium and zirconium, a shows the wt.% of palladium and is a=0.01-3, b, c, d, e and f shows atomic ratios of respective components and, when b is 10, c is 0.1-10, d is 0.01-5 and e is 0.01-5 and f is the number of oxygen atoms necessary for satisfying the valencies of respective components. |
