Abstract: A double-layer three-way catalyst is presented, which is formed from a catalytic coating applied directly to an inert honeycomb and a catalytically active coating thereon, and is suitable especially for cleaning of exhaust gases of motor vehicles with gasoline-operated internal combustion engines. The catalyst contains, in each layer, an active aluminum oxide and a cerium/zirconium mixed oxide, both of which are catalytically activated by palladium. The second layer on the gas side contains not only palladium but also rhodium, which is applied to the active aluminum oxide and the cerium/zirconium mixed oxide of the second layer in addition to the palladium. The cerium/zirconium mixed oxide of the second layer has a higher zirconium oxide content than the cerium/zirconium mixed oxide of the first layer. The catalyst is notable for exceptional activity coupled with outstanding aging stability.

Abstract: A one-layer three-way catalyst is described for the cleaning of the exhaust gases of internal combustion engines with outstanding activity and thermal stability. The catalyst comprises an active aluminum oxide, a first cerium/zirconium mixed oxide and a second cerium/zirconium mixed oxide. The first cerium/zirconium mixed oxide has a higher zirconium oxide content than the second mixed oxide. The first cerium/zirconium mixed oxide is catalytically activated with rhodium and the second cerium/zirconium mixed oxide with palladium.

Abstract: A one-layer three-way catalyst is described for the cleaning of the exhaust gases of internal combustion engines with outstanding activity and thermal stability. The catalyst comprises an active aluminum oxide, a first cerium/zirconium mixed oxide and a second cerium/zirconium mixed oxide. The first cerium/zirconium mixed oxide has a higher zirconium oxide content than the second mixed oxide. The first cerium/zirconium mixed oxide is catalytically activated with rhodium and the second cerium/zirconium mixed oxide with palladium.