Exhaust gas purifying system

摘要

An exhaust gas purifying system for efficiently purifying HC discharged at time of cold starting of an internal combustion engine. This exhaust gas purifying system includes an HC adsorbing/purifying catalyst (10) disposed in an exhaust gas passage, and a three-way catalyst (20) disposed upstream of the HC adsorbing/purifying catalyst (10) in the exhaust gas passage. The HC adsorbing/purifying catalyst (10) includes a monolithic carrier (1) having a sectional diameter (d) and a length (L) set in a relationship represented by 0.70≤L/d, and a hydrocarbon adsorbent layer (2) and a purifying catalyst layer (3), which are formed on the monolithic carrier (1).