| 摘要 |
A catalyst for purification of exhaust gases, comprising a monolithic carrier and a catalyst layer formed thereon for reduction of the carbon monoxide, hydrocarbons and nitrogen oxides emitted from internal combustion engines, wherein (1) the catalyst layer contains catalyst particles each comprising a heat-resistant inorganic oxide and at least one noble metal selected from Pt, Pd and Rh, loaded thereon, (2) the catalyst layer contains, as a whole, three noble metals of Pt, Pd and Rh, (3) the catalyst layer contains, at any position ranging from the outer surface to the midpoint of the thickness, catalyst particles comprising a heat-resistant inorganic oxide and 2-10% by weight, based on the inorganic oxide, of Pd loaded thereon, and (4) the catalyst layer has, at the outer surface, exposed catalyst particles comprising an heat-resistant inorganic oxide and at least Rh loaded thereon.
|
