| abstract |
The present invention addresses the problem of increasing the NO x purification rate when an SCR catalyst is in an inactive state in an exhaust purification system of an internal combustion engine provided with an oxidation catalyst and an SCR catalyst disposed downstream of the oxidation catalyst. In order to solve this problem, the present invention is an exhaust purification system of an internal combustion engine provided with an oxidation catalyst disposed in an exhaust passage of an internal combustion engine, an SCR catalyst disposed in an exhaust passage downstream of the oxidation catalyst, and a supply device for supplying unburned fuel to the oxidation catalyst when the SCR catalyst is inactive, wherein the amount of NO 2 flowing into the SCR catalyst is increased by reducing the amount of unburned fuel supplied when the internal combustion engine is operating with a low load. |