| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a new catalyst for cleaning exhaust gas to remove NO<SB>x</SB>, wherein problems of the conventional techniques are solved. <P>SOLUTION: The catalyst for cleaning exhaust gas includes a carrier base material S, a palladium-deposited layer Pd, a rhodium-deposited layer Rh and a platinum-deposited layer Pt. The concentration of the palladium deposited on the palladium-deposited layer is made higher than that of the palladium deposited on each of the rhodium-deposited layer and the platinum-deposited layer. The concentration of the rhodium deposited on the rhodium-deposited layer is made higher than that of the rhodium deposited on each of the palladium-deposited layer and the platinum-deposited layer and the concentration of the platinum deposited on the platinum-deposited layer is made higher than that of the platinum deposited on each of the palladium-deposited layer and the rhodium-deposited layer. On the carrier base material, the rhodium-deposited layer is arranged at least partially on the downstream side of the palladium-deposited layer in an exhaust gas current and/or at least partially on the downside of the palladium-deposited layer. The platinum-deposited layer is arranged at least partially on the downstream side of each of the palladium-deposited layer and the rhodium-deposited layer in the exhaust gas stream. <P>COPYRIGHT: (C)2010,JPO&INPIT |
