APPARATUS FOR TREATING EXHAUST GAS OF LEAN BURN INTERNAL COMBUSTION ENGINE COMPRISING OXIDATION CATALYST AND METHOD FOR RECOVERING THE OXIDATION ACTIVITY OF AN OXIDATION CATALYST

摘要

An apparatus comprises a lean -burn internal combustion engine, engine management means and an exhaust system for treating exhaust gas of the engine, which exhaust system comprises a first oxidation catalyst disposed on a first honeycomb monolith substrate, which first oxidation catalyst comprises platinum supported on a first metal oxide support comprising at least one reducible oxide, wherein the first oxidation catalyst is substantially free of alkali metals and alkaline earth metals, wherein the engine management means is arranged, when in use, intermittently to modulate the lambda composition of the exhaust gas entering the first oxidation catalyst to a rich lambda composition. Furthermore, a method of recovering an oxidation activity of an oxidation catalyst aged in an exhaust gas of a lean -burn internal combustion engine is disclosed.