Automotive catalyst composites having a two-metal layer

摘要

Provided are catalyst composites whose catalytic material is effective to substantially simultaneously oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides. The catalyst composites have a two-metal layer on a carrier, the two-metal layer comprising a rhodium component supported by a first support comprising a refractory metal oxide component or a first ceria-zirconia composite; a palladium component supported by a second support comprising a second ceria-zirconia composite; one or more of a promoter, stabilizer, or binder; wherein the amount of the total of the first and second ceria-zirconia composites in the two-metal layer is equal to or greater than the amount of the refractory metal oxide component. Methods of making and using the same are also provided.

主权项

1. An automotive catalyst composite comprising:
a catalytic material on a carrier, the catalytic material comprising a two-metal layer that comprises: a rhodium component supported by a first support comprising a refractory metal oxide component and optionally further a first ceria-zirconia composite; a palladium component supported by a second support comprising a second ceria-zirconia composite; one or more of a promoter, stabilizer, or binder; wherein the catalytic material is effective for three-way conversion (TWC) to substantially simultaneously oxidize carbon monoxide and hydrocarbons and reduce nitrogen oxides, and wherein the amount of the total of the first ceria-zirconia composite, if present, and the second ceria-zirconia composite in the two-metal layer is equal to or greater than the amount of the refractory metal oxide component.