Catalyst for purifying exhaust gas

Abstract

Abstract PURPOSE:To enhance purification capacity, by supporting specific composite oxide consisting of sesqioxide of a lanthanide metal and metal palladium and platinum or platinum and rhodium by a cerium-containing alumina coating layer. CONSTITUTION:Commerial ceria and lanthanum oxide or neodium oxide are impregnated with a predetermined amount of palladium chloride to support the same and the impregnated one is baked at about 600 deg.C or more to obtain a composite oxide powder represented by Ln2PdO4. This composite oxide powder and a cerium-containing activated alumina are mixed with a nitric acid/boehmite/alumina sol and the resulting mixture is ground to obtain a slurry which is, in turn, applied to the surface of a monolithic carrier base material based on cordierite and the coated base material is dried and baked to obtain a catalyst carrier. After platinum or platinum and rhodium is supported by this catalyst carrier, the supported carrier is baked at about 550-750 deg.C for about 0.5-2hr to obtain a catalyst.

Inventors

• 👤 Yoshiyuki Eto
• 👤 江渡　義行
• 👤 Goji Masuda
• 👤 剛司 増田

Bibliographic Details