| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust gas purifying catalyst for purifying a low temperature exhaust gas which is capable of restoring the catalytic performance by the control of the fuel jetting quantity or the like in the case that the catalytic performance is deteriorated by the oxidation of platinum during the operation, and to provide a manufacturing method thereof and an exhaust gas purifying system. SOLUTION: The exhaust gas purifying catalyst is formed by supporting platinum as an active component on a heat resistant inorganic oxide support. When the platinum supported on the heat resistant inorganic oxide support is measured by photoelectron spectroscopy, the ratio of the area integrated value of the peak of energy state having the maximum value in 74 eV(PtO), 73 eV(PtO1-x) and 71 eV(Pt) is expressed by (S1(PtO))/(S2(Pt1-x)+S(Pt))=0.01-0.4. The manufacturing of the catalyst is attained by supporting platinum on the heat resistant inorganic oxide using a mixed solution of a water soluble platinum raw material, which contains a carboxylic acid such as citric acid and has (the number of carboxyl groups)/(the number of mols of platinum) of 0.5-4.0 and pH<7.0. |
