| 摘要 |
PURPOSE:To obtain a catalyst capable of efficiently removing particulate substances in exhaust gas by providing a catalyst components consisting of inorganic oxide, noble metal, and rhodium and incorporating rhodium only into the upper layer part of a catalyst component holding layer. CONSTITUTION:Catalyst components containing refractory inorganic oxide, such as alumina and silica, palladium and/or platinum, and rhodium are held by a refractory three-dimensional structure, such as ceramic foam, and this rhodium is incorporated only into the upper layer part having a thickness equivalent to <=80% of the thickness of the catalyst component holding layer. The resulting catalyst for engine cleanup is excellent in the property of combustive removal of harmful components, such as unburnt hydrocanbon and carbon monoxide, other than carbonaceous particulates from low temp. and is reduced in the oxidizing power of sulfur dioxide. |
