| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively use a reducing agent by suppressing supply of the reducing agent to an active ingredient which is not active yet. <P>SOLUTION: A catalyst support 20A arranged in an exhaust passage is coated with a first base material 20B supporting the active ingredient reducing NOx with the supply of ammonia A as the reducing agent, a second base material 20C adsorbing the ammonia A at an exhaust temperature below the catalytic active temperature and releasing the ammonia A at the exhaust temperature equal to and above the catalytic active temperature and a third base material 20D such as γ-alumina capable of suppressing the release of the ammonia therefrom. The first base material 20B, the second base material 20C and the third base material 20D are applied in the order of the second base material 20C, the third base material 20D and the first base material 20B to form a layered state. A base material having the functions of both the first base material 20B and the second base material 20C can be applied. <P>COPYRIGHT: (C)2012,JPO&INPIT |
