EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To inhibit hydrogen cyanide from being discharged to atmospheric air by arranging HC adsorption catalyst in an engine exhaust passage in an upstream of a selective reduction catalyst.

SOLUTION: An urea adsorption type selective reduction catalyst 14 is arranged in the engine exhaust passage in an exhaust emission control device for an internal combustion engine. NOx contained in exhaust gas is reduced by the selective reduction catalyst 14 by supplying urea in exhaust gas flowing into the selective reduction catalyst 14 from an urea supply valve 16. A HC adsorption catalyst 12 for adsorbing HC in exhaust gas is arranged in the engine exhaust passage in the upstream of the selective reduction catalyst 14 in order to inhibit formation of hydrogen cyanide.

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