EXHAUST PURIFICATION DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

An ambient NOx adsorption catalyst that can adsorb NOx contained in an exhaust gas in the presence of CO under standard conditions is placed in an engine exhaust gas passage, in an internal combustion engine. Until an engine post-initiation catalyst is activated, the amounts of a high-boiling-point hydrocarbon and an unsaturated hydrocarbon that are contained in the exhaust gas flowing into the catalyst are reduced so that the NOx-adsorbing activity cannot be deteriorated by the adhesion activity of the hydrocarbons while maintaining the CO concentration in the exhaust gas flowing into the catalyst at a level higher than the concentration required for the adsorption of NOx.