| 摘要 |
PURPOSE:To enhance the purification performance and durability of catalysts, by immersing a catalyst carrier in an alumina slurry blended with a specific amount of superfine particles of lanthanum and a reducing agent such as formic acid, and baking the catalyst carrier, then soaking it in an aqueous solution of a main catalyst metal. CONSTITUTION:An aqueous solution of catalyst carrier containing superfine particles of lanthanum having an average particle diameter of at most 5,000Angstrom and one kind of reducing agent selected from among sodium borohydride, formic acid and oxalic acid, mixed at mol ratio of 1:17-50, is added to alumina slurry. A catalyst carrier is soaked in the alumina slurry and baked. After this, the catalyst carrier thus coated with alumina is immersed in an aqueous solution of a main catalyst metal and baked to obtain a catalyst for exhaust gas purification. In this way, an alumina layer is uniformly formed on the surface of the catalyst carrier, and the main catalyst and superfine particles of lanthanum are carried uniformly on the alumina layer. |
