EXHAUST GAS PURIFICATION DEVICE FOR INTERNAL-COMBUSTION ENGINE

摘要

The purpose of the present invention is to remove HC, CO and ammonia satisfactorily from an exhaust gas, the HC, CO and ammonia having flowed out from a filter (SCRF) on which an SCR catalyst is supported. According to the present invention, a rear-stage catalyst (8) is provided in an exhaust passage of an internal-combustion engine on the downstream side of the SCRF along the flow of the exhaust gas. The rear-stage catalyst (8) is configured so as to include: an adsorption reduction part (81c) which adsorbs ammonia and reduces NOx with the ammonia acting as a reducing agent; a first oxidation part (81b) which oxidizes ammonia; and a second oxidation part (82) which oxidizes HC and CO.