| 摘要 |
<P>PROBLEM TO BE SOLVED: To produce a filter catalyst for exhaust gas purification which suppresses: lowering of NO<SB>x</SB>purification performance after high temperature endurance by suppressing solid solution of an NO<SB>x</SB>occlusion material into a filter base material; increase of pressure loss; and lowering of PM collection rate. <P>SOLUTION: The NO<SB>x</SB>occlusion material and a noble metal are directly carried by ion exchange on the filter base material formed of zeolite. Since the NO<SB>x</SB>occlusion material does not form a solid solution with zeolite, NO<SB>x</SB>occlusion performance is not lost by the solid solution. Since the NO<SB>x</SB>occlusion material and noble metal are carried on zeolite in an extremely highly dispersed state, they have very high activity. No coating layer is formed and hence the increase of pressure loss is suppressed. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
