| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nitrogen oxide adsorbent, which can adsorb a nitrogen oxide sufficiently even at a low temperature region (for example, 200°C or lower). <P>SOLUTION: The nitrogen oxide adsorbent comprises a porous carrier composed of at least one metallic oxide selected from a group consisting of ceria, magnesia, and alumina, a first nitrogen oxide adsorbent layer supported by the porous carrier and provided with at least one active metal element selected from a group consisting of platinum, rhodium, palladium, iridium, gold, silver, cobalt, nickel, copper, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, indium, and tin, and a second nitrogen oxide adsorbent layer formed on the surface of the first nitrogen oxide adsorbent layer, provided with a ceria-containing porous carrier containing mainly ceria, and containing no active metal element essentially. <P>COPYRIGHT: (C)2009,JPO&INPIT |
