Exhaust gas purifying system for an internal combustion engine

摘要

An engine is provided with an NOx catalyst (42A) in its exhaust system (40) and an amount of reduction components (HC components) in the exhaust gas is suitably increased through a fuel adjunction nozzle to thereby attain the NOx purification effect by the catalyst (42A). Only precious metal catalyst is carried in an upstream side portion R1 as the exhaust gas flow path in a honeycomb-shaped structure forming the NOx catalyst (42A) but no NOx absorbent is carried therein. Also, both the precious metal catalyst and the NOx absorbent are carried at a predetermined density in a downstream side portion R2 as the exhaus gas flow path in the honeycomb-shaped structure forming the NOx catalyst (42A).