초록 ▼

A stable, close-coupled catalyst, an article comprising the close-coupled catalyst and a related method of operation. The close-coupled catalyst comprises a catalyst support and a palladium catalytic component. Preferably and optionally, there are stabilizers including alkaline metal oxide, and rare

A stable, close-coupled catalyst, an article comprising the close-coupled catalyst and a related method of operation. The close-coupled catalyst comprises a catalyst support and a palladium catalytic component. Preferably and optionally, there are stabilizers including alkaline metal oxide, and rare earth metal components selected from the neodymium and lanthanum components. The close-coupled catalyst composition includes substantially no additional oxygen storage component such as praseodymium or cerium compounds. There is preferably a catalyst such as a three-way catalyst downstream of the close-coupled catalyst. The downstream catalyst preferably includes an oxygen storage component such as cerium oxide or praseodymium oxide.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method comprising the steps of:operating a gasoline engine, having an exhaust gas outlet or an exhaust gas manifold outlet;passing an exhaust gas stream comprising carbon monoxide, hydrocarbons, and optionally nitrogen oxide, from the exhaust gas outlet or the exhaust

[ What is claimed is:] [1.]1. A method comprising the steps of:operating a gasoline engine, having an exhaust gas outlet or an exhaust gas manifold outlet;passing an exhaust gas stream comprising carbon monoxide, hydrocarbons, and optionally nitrogen oxide, from the exhaust gas outlet or the exhaust manifold outlet of the gasoline engine to a close coupled catalyst, the close coupled catalyst comprising a close coupled catalyst composition;contacting the exhaust gas with the close coupled catalyst composition, the close coupled catalyst composition having substantially no oxygen storage components, the catalyst composition comprising:a support;a palladium component;optionally, at least one alkaline metal oxide selected from the group consisting of strontium oxide, calcium oxide and barium oxide;optionally, at least one platinum group metal component selected from the group consisting of platinum, rhodium, ruthenium and iridium components;optionally, at least one rare earth oxide selected from the group consisting of neodymium oxide and lanthanum oxide; andoptionally, a zirconium oxide;oxidizing at least some of the hydrocarbon and only a portion of the carbon monoxide in the presence of the close coupled catalyst; andpassing the exhaust gas from the close-coupled catalyst to a downstream catalyst, the downstream catalyst comprising an oxygen storage component selected from the group consisting of cerium components and praseodymium components.