Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas of internal combustion engine

摘要

An exhaust gas purification apparatus for use in an internal combustion engine (99) is disclosed which comprises an exhaust gas duct connected to said engine (99), through which the exhaust gas flows, and a catalyst (18) disposed in said exhaust gas duct, for adsorbing NOx under lean combustion conditions. A manifold catalyst (19) may be disposed in said exhaust gas duct after the engine (99) upstream of said catalyst (18), which has the functions of a three way catalyst and a combustion catalyst. The manifold catalyst (19) arises its working temperature in a short time after engine starting in order to allow the purification of hydrocarbons (HC) and carbon monoxide (CO) immediately after engine starting. Alternatively a three way catalyst or a combustion catalyst may be disposed in said exhaust gas duct at the upstream of said catalyst (18).