| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device of an internal combustion engine capable of promptly starting NO<SB>x</SB>reduction action at engine start-up. <P>SOLUTION: In the exhaust emission control device, a NO<SB>x</SB>selective reduction catalyst 15 is disposed in an engine exhaust passage. A urea aqueous solution is supplied to the NO<SB>x</SB>selective reduction catalyst 15. The NO<SB>x</SB>selective reduction catalyst 15 adsorbs ammonia generated from the urea aqueous solution. The adsorbed ammonia selectively reduces NO<SB>x</SB>. If an amount of the ammonia adsorbed to the NO<SB>x</SB>selective reduction catalyst 15 is smaller than a prescribed target adsorption amount at the engine stop, urea in an amount required to make an amount of the ammonia adsorbed to the NO<SB>x</SB>selective reduction catalyst 15 equivalent to the target adsorption amount is supplied to the NO<SB>x</SB>selective reduction catalyst 15 at the engine stop. <P>COPYRIGHT: (C)2009,JPO&INPIT |
