| 摘要 |
PURPOSE:To improve purification activity and durability above 600 deg.C by providing a specific metallic oxide layer which carriers Rh on a two-tiered oxide layer which consists of a specific metallic oxide carrying Pd provided on a catalyst carrier. CONSTITUTION:Wash coat slurry is produced by ball-milling alumina and aluminum nitrate with water and nitric acid. Then slurry is caused to stick to a monolithic carrier by immersing the latter in the slurry and after removal of surplus slurry, the sticking slurry is dried and calcined to coat the alumina with a thickness of 10-50mum. Next, the carrier is soaked in an aqueous solution of cerium nitrate and then is dried. After this, the carrier is again immersed in an aqueous solution of zirconium nitrate and then is subjected to drying and calcining process so that it carries cesium oxide and zirconium oxide. Furthermore, the carrier is soaked in an aqueous nitric acid solution of dinitrodiamine palladium, and dried, calcined and caused to carry Pd. Besides the carrier is caused to carry Rh in the same process to obtain a catalyst for exhaust purification. |
