| 摘要 |
<P>PROBLEM TO BE SOLVED: To secure a nitrogen oxide clean-up performance even under such an operating condition that a selective reduction catalyst does not function effectively in an exhaust emission control device of an internal combustion engine. <P>SOLUTION: This exhaust emission control device of the internal combustion engine includes a storage/reduction catalyst 1 which stores the nitrogen oxides contained in the exhaust emission from the internal combustion engine 4 under an oxidizing atmosphere, reduces the nitrogen oxides under a reducing atmosphere, and generates ammonia from the nitrogen oxides and the selective reduction catalyst 2 which stores the ammonia and reduces the nitrogen oxides using the ammonia as a reducer. The exhaust emission control device further includes a reducing capability evaluation means 3a for quantitatively evaluating the nitrogen oxide reducing capability of the selective reduction catalyst 2 and a control means 3b for controlling so as to cover the lowering of the reducing capability by the nitrogen oxide reducing capability of the storage/reduction catalyst 1. <P>COPYRIGHT: (C)2010,JPO&INPIT |
