| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a catalyst for cleaning an exhaust gas, in which noble metals are neither alloyed nor deteriorated even at high temperature. <P>SOLUTION: The catalyst for cleaning an exhaust gas is provided with: a carrier having a through-hole penetrated in the axial direction; and a catalyst-coated layer which is formed on the inside surface of the through-hole and contains the noble metal and a fire-resistant inorganic oxide. The through-hole is used as a flow passage of the exhaust gas. The catalyst-coated layer formed in an A region to be positioned in the upstream part of the flow passage in the flow direction of the exhaust gas contains Rh as the noble metal and a noble metal other than Rh by 1:0-0.5 weight ratio of Rh to the noble metal other than Rh. The catalyst-coated layer formed in a B region to be positioned in the downstream part of the flow passage in the flow direction of the exhaust gas contains Rh as the noble metal and the noble metal other than Rh, the weight of which is heavier than that of Rh as the noble metal. <P>COPYRIGHT: (C)2007,JPO&INPIT |
