EXHAUST GAS PURIFICATION SYSTEM FOR INTERNAL-COMBUSTION ENGINE

An object of the present invention is to suppress HC, CO, and NOx from being discharged to the outside when a filter regeneration process is executed in an exhaust gas purification system for an internal combustion engine provided with a filter including an SCR catalyst carried thereon. In the present invention, a post-catalyst is provided for an exhaust gas passage disposed on a downstream side from the filter. The post-catalyst has an oxidizing function, and the post-catalyst has such a function that the production of N 2 based on the oxidation of ammonia is facilitated in a predetermined first temperature area. Further, when the filter regeneration process is executed, the temperature of the post-catalyst is adjusted to be in the first temperature area while adjusting the temperature of the filter to be in a predetermined second temperature area lower than a filter regeneration temperature during a certain period of time.