To suppress the exhaustion of hydrogen sulfide from an internal combustion engine to be operated in a lean-burn condition.
This exhaust emission control device for the internal combustion engine comprises a NOx purifying catalyst provided in an exhaust gas duct of the internal combustion engine into which exhaust gas of lean air-fuel ratio and exhaust gas of rich air-fuel ratio or stoichimetric form flows for trapping NOx and SOx in exhaust gas in a lean condition, a hydrogen sulfide trapping catalyst provided at the rear stage thereof for trapping hydrogen sulfide, and a heating means for heating the hydrogen sulfide trapping catalyst. The air-fuel ratio is set lean when the amount of S trapped by the hydrogen sulfide trapping catalyst reaches a preset amount. The heating means is used for increasing the temperature of the hydrogen sulfide trapping catalyst to a preset temperature or higher to permit the release of all or part of S-component trapped by the hydrogen sulfide trapping catalyst as SOx.
IIZUKA HIDEHIRO
HIGASHIYAMA KAZUHISA
KITAHARA YUICHI
