| 摘要 |
<P>PROBLEM TO BE SOLVED: To produce an exhaust gas cleaning catalyst which can maintain the concentration of an NO<SB>x</SB>-occluding agent in a catalyst support layer at a preferable concentration. <P>SOLUTION: The exhaust gas cleaning catalyst comprises a substrate, a catalyst support layer which is formed on the surface of the substrate and supports a noble metal and an NO<SB>x</SB>-occluding agent, and an underlayer which is a part of the substrate, is formed under the catalyst support, and supports the NO<SB>x</SB>-occluding agent. In the part wherein the catalyst support layer is in contact with the underlayer, the concentration of the NO<SB>x</SB>-occluding agent supported by the under layer is higher than the concentration of the NO<SB>x</SB>-occluding agent supported by the catalyst support layer. The preparation method for the catalyst is also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
