초록 ▼

Provided are catalyst composites comprising: a catalytic material on a carrier, the catalytic material comprising a precious metal selected from a palladium component and an oxygen storage component, the oxygen storage component being present in an amount of at least 10% by weight, wherein substanti

Provided are catalyst composites comprising: a catalytic material on a carrier, the catalytic material comprising a precious metal selected from a palladium component and an oxygen storage component, the oxygen storage component being present in an amount of at least 10% by weight, wherein substantially all of the oxygen storage component is in intimate contact with the palladium component and the catalytic material is effective to substantially simultaneously oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides. A catalyst composite comprising: a catalytic material on a carrier, the catalytic material comprising a palladium component and a ceria-zirconia composite support, the ceria being present in an amount in the range of 10 to 70% by weight, wherein substantially all of the ceria is in intimate contact with at least a portion of the palladium component. Methods of making and using these catalysts along with systems containing these catalysts are also provided.

대표청구항 ▼

What is claimed is: 1. An exhaust system effective to substantially simultaneously oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides, the system comprising a combination of a first composite and a second composite, wherein the first composite comprises a precious metal that is a pa

What is claimed is: 1. An exhaust system effective to substantially simultaneously oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides, the system comprising a combination of a first composite and a second composite, wherein the first composite comprises a precious metal that is a palladium component and an oxygen storage component that comprises at least a first ceria-zirconia composite and a second ceria-zirconia composite, the oxygen storage component being present in an amount of at least 10% by weight, wherein substantially all of the oxygen storage component is in intimate contact with the palladium component; wherein the first composite is substantially free of other precious metal components; and the second composite comprises a catalytic material having a rhodium component present in a low amount;wherein the first composite comprises a first catalytic material on a carrier, the first catalytic material comprising at least two layers, the first catalytic material comprising:an inner layer above the carrier comprising the palladium component in an amount in the range of 30 to 70% by weight of palladium in the catalytic material, a first high surface area refractory metal oxide support, the first ceria-zirconia composite, and one or more of a promoter, stabilizer, or binder; andan outer layer deposited on the inner layer comprising the palladium component in an amount in the range of 30 to 70% by weight of palladium in the catalytic material, a second high surface area refractory metal oxide support different from the first high surface area refractory metal oxide support, the second ceria-zirconia composite, and one or more of a promoter, stabilizer, or binder.