EXHAUST EMISSION CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine, the emission control performance of which is improved by positively separating HC from CO to preferentially cause an oxidation/reduction reaction between CO and NOx in the presence of a catalyst.

SOLUTION: A three-way catalyst (30) is composed of a small pore catalyst (30a) having a group of small pores of the average opening size smaller than the molecular size of HC on a washcoat of the three-way catalyst and a large pore catalyst (30b) having a group of large pores of the average opening size larger than the molecular size of HC on the washcoat.

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