CATALYST FOR PURIFYING EXHAUST GAS OF ENGINE

摘要

PURPOSE:To maintain the excellent purification performance and the durability of the titled catalyst by providing an alpha-Al2O3 layer incorporating Pt on a catalytic carrier of an upstream side and providing a gamma-Al2O3 layer incorporating a catalytic component such as Pd other than Pt on the catalytic carrier of a downstream side. CONSTITUTION:The first catalyst 3 of an upstream side is formed by providing an alpha-Al2O3 layer 7 deposited with Pt, Rh on the surface part of a catalytic carrier 6 (monolithic wall body). The second catalyst 4 of a downstream side is formed by providing gamma-Al2O3 layer 8 deposited with Pd on the surface part of the catalytic carrier 6. A catalyst for purifying an exhaust gas is formed by interposing a monolith type catalyst 5 consisting of the first catalyst 3 of the upstream side and the second catalyst 4 of the downstream side in the inside of a catalytic vessel 2 formed on the way of an exhaust system 1. Pt and Pd are excellent in the purification performance of CO, HC contained in the exhaust gas and Rh is excellent in the purification performance of NOx and the purification of the harmful components contained in the exhaust gas is enabled at once with the three components.