| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device appropriately controlling ammonia production in a storage reduction catalyst and improving NOx conversion performance. <P>SOLUTION: This exhaust emission control device includes: the storage reduction catalyst 1 occluding NOx in exhaust gas in an internal combustion engine 4 under an oxidizing atmosphere, reducing NOx in a reduction atmosphere, and forming ammonia from NOx; a selective reduction catalyst 2 interposed downstream of the storage reduction catalyst 1 in an exhaust passage 7, occluding ammonia, and reducing NOx with ammonia as the reducing agent; a storage capacity calculation means 3a estimating or detecting the storage capacity of ammonia occluded by the selective reduction catalyst 2; and a control means 3c controlling the production of ammonia in the storage reduction catalyst 1 based on the storage capacity. <P>COPYRIGHT: (C)2010,JPO&INPIT |
