| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a catalyst for cleaning an exhaust gas having sufficiently high temperature durability and sufficiently high sulfur-poisoning durability and capable of exhibiting sufficiently high catalytic activity over a wide temperature range. <P>SOLUTION: The catalyst for cleaning the exhaust gas is provided with two kinds or more of NOx occlusion parts containing an oxide composite body having a different composition respectively, and the oxide composite body contains at least one of first metal element selected from the group consisting of an alkali metal and an alkaline earth metal, and at least one of second metal element selected from the group consisting of rare earth metal. A standard deviation of distribution of a ratio ([peak area of first metal element]/[total of peak area of first metal element and peak area of second metal element]) of a peak area of the first metal element relative to the total of the peak area of the first metal element and the peak area of the second metal element determined TEM-EDX analysis at 20 or more measurement points of 10 nm square on a surface of the oxide composite body is 10% or lower. The two kinds or more of NOx occlusion parts are arranged such that they are contacted with the exhaust gas in the order from the NOx occlusion part containing the oxide composite body in which a value of a content molar ratio ([first metal]/[second metal]) of the first metal element relative to the second metal element is smaller. <P>COPYRIGHT: (C)2009,JPO&INPIT |
