Patent ID: 9662612
Date: 2017-05-30
CPC Classifications: B01D,F01N,Y02T

Claim:
1. An exhaust gas purification apparatus for an internal combustion engine, comprising: a filter which is provided for an exhaust gas passage of the internal combustion engine and which traps particulate matter contained in an exhaust gas, the filter including a selective catalytic reduction NOx catalyst carried thereon for reducing NOx contained in the exhaust gas by using ammonia as a reducing agent; an ammonia supply device configured to supply ammonia or an ammonia precursor to the filter; and a post-catalyst which is provided for the exhaust gas passage on a downstream side from the filter, wherein the post-catalyst is constructed to include: an adsorption reduction part which has a function to adsorb ammonia and a function to reduce NOx by using ammonia as the reducing agent; a first oxidation part which is positioned on a downstream side from the adsorption reduction part along with a flow of the exhaust gas and which has a function to oxidize ammonia; and a second oxidation part which is positioned on a downstream side from the adsorption reduction part and the first oxidation part along with the flow of the exhaust gas, which has an oxidation ability higher than that of the first oxidation part, and which has a function to oxidize HC and CO.