| 摘要 |
PROBLEM TO BE SOLVED: To effectively clean HC, CO and microparticles contained in an exhaust gas from a diesel engine continuously. SOLUTION: In a catalyst 3 for oxidizing the upstream of an exhaust gas with characteristics such as comparatively higher exhaust temperatures and free from the deterioration of a catalytic oxidation performance due to PM accumulation and, on the other hand, with such a shortcoming that sulphate would be produced, PM is effectively reduced by enlarging the grain diameter of Pt, increasing the bearing amount of a wash coat, decreasing the bearing amount of Pt slightly, and reducing an organic soluble component(SOF) while suppressing the production of sulphate. On the other hand, the oxidative activity performance of a catalyst 5 for oxidizing the downstream of an exhaust gas at low exhaust temperatures, susceptible of the deterioration of its oxidative active performance clue to the PM accumulation, is improved by increasing the bearing amount of Pt slightly and suppressing the adsorption and accumulation of PM. |
