| 摘要 |
PROBLEM TO BE SOLVED: To provide a catalyst for cleaning exhaust gas having the cleaning performance of hydrocarbon and also having the improved cleaning performance of carbon monoxide and NOx. SOLUTION: In the catalyst for cleaning the exhaust gas constituted of an upstream side catalyst arranged at the upstream side with respect to exhaust gas flow and a downstream side catalyst arranged at the downstream side each of which catalysts has a cylindrical carrier having many through-holes penetrating in the axial direction, a carrying layer of a refractory inorganic oxide formed at the inner surface sectioning the through holes and catalyst component held on the carrying layer, the upstream side catalyst contains one kind noble metal selected among palladium, (palladium and rhodium) or (palladium and platinum), and the carrying layer is constituted of the alumina containing at least barium and lanthanum, and the downstream side catalyst contains at least one noble metal among platinum, palladium and rhodium, and the carrying layer is constituted of the aluminum containing the lanthanum, and of one kind selected from among serium or a solid solution of the serium and zirconium and a solid solution of serium, zirconium and yttrium. |
