Exhaust gas treatment device for lean burn internal combustion engine including oxidation catalyst and method for recovering oxidation activity of oxidation catalyst

摘要

PROBLEM TO BE SOLVED: To provide a device for recovering an oxidation activity caused by platinum whose oxidation catalyst is oxidized at a high temperature. A lean-burn internal combustion engine, an engine management means, and an exhaust system for treating exhaust gas of the engine are provided, the exhaust system being a first honeycomb monolith substrate. Of oxidation catalyst, the first oxidation catalyst comprising 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, the engine management means, in use, intermittently adjusts the lambda composition of the exhaust gas entering the first oxidation catalyst to a rich lambda composition. [Selection diagram] Fig. 3