| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas cleaning device capable of reducing particulate matter discharged outside, while suppressing intergranular corrosion or strength lowering of a substrate due to alkali metals. <P>SOLUTION: A catalyst layer 30 is formed on the straight flow type honeycomb-like substrate 22, the catalyst layer 30 is composed of a plurality of catalyst layers formed by stacking a lower catalyst layer 34 formed on the surface of the substrate 22 and an upper catalyst layer 32 formed on the exhaust gas side from the lower catalyst layer 34, the lower catalyst layer 34 is provided with heat resisting oxide carriers 36, 38 and a catalyst metal carried on the carriers 36, 38, and the upper catalyst layer 32 is provided with the heat resisting oxide carriers 36, 38, a catalyst metal carried on the carriers 36, 38, and a needle crystalline promotor 37 containing the alkali metal and aluminum carried on the heat resisting oxide carriers 36, 38. <P>COPYRIGHT: (C)2009,JPO&INPIT |
