| 摘要 |
PURPOSE:To enhance resistance to heat and resistance to lead and to improve purifying performance by successively depositing a coated layer having specified narrow pore diameter, platinum and rhodium components, the coated layer having specified narrow pore diameter and platinum component on a carrier base material to prepare a catalyst for purifying exhaust gas. CONSTITUTION:A coated layer having <=100Angstrom peak of narrow pore diameter and consisting of activated alumina and rare earth metallic oxide is formed on a carrier base material. This coated layer is impregnated with an aq. soln. contg. chloride of at least Pt and Rh selected from chloride of Pt, Rh and Pd and thereafter calcined to deposit at least Pt and Rh. Then a coated layer having 200-500Angstrom peak of narrow pore diameter and consisting of activated alumina and rare earth metallic oxide is formed on this layer. Furthermore it is impregnated with a nitric acid soln. of dinitrodiamineplatinum soln. and thereafter calcinated to deposit Pt in a prescribed amount and a catalyst for purifying exhaust gas is produced. |
