| 摘要 |
PURPOSE:To improve purifying capacity for hydrocarbons, CO, and NOX of a waste gas purifying catalyst by providing a coated layer consisting of powder of perovskite type compound oxide, activated alumina, etc. to the surface of a monolithic carrier, and depositing at least one kind among Pt, Rh, and Pd to the coated layer. CONSTITUTION:A specified amt. of aq. soln. of nitrate of a rare earth metal is immersed in an activated alumina carrier by the immersion method, and the carrier is after drying calcined at 600-650 deg.C in the air. Then, a slurry prepd. by crushing a mixture of powder of rare earth metal oxide, said activated alumina carrier, and perovskite type compound oxide powder is coated on a base material of monolithic carrier comprising cordierite. A catalyst carrier is obtd. by calcining the coated product at 650-850 deg.C after drying the coated product. Obtd. carrier is immersed in aq. soln. of at least one kind of salt of Pt, Rh, or Pd. After drying the immersed product, it is calcined at 500-700 deg.C for 0.5-2hr to obtain thus a waste gas purifying catalyst. |
