SYSTEM FOR PURIFYING EXHAUST GAS

摘要

PROBLEM TO BE SOLVED: To provide a simple system for purifying exhaust gas, by which the purification efficiency of a cold hydrocarbon(HC) can be enhanced. SOLUTION: This exhaust gas purifying system for efficiently purifying HC discharged from an internal-combustion engine at time of cold starting has an HC adsorption/purification catalyst disposed on an exhaust gas passage and a ternary catalyst disposed on the upstream side of the HC adsorption/ purification catalyst in the exhaust gas passage. The HC adsorption/purification catalyst has a monolithic carrier satisfying 0.45<=L/d (wherein d is the diameter of the cross-sectional area of the carrier; L is the full length of the carrier) and a hydrocarbon adsorbing material layer and a purification catalyst layer which are formed on the monolithic carrier.