Catalyst of rhodium on zirconia
AssigneeFord Motor Company
InventorsHaren S. Gandhi, Joseph T. Kummer, Mordecai Shelef, Henryk K. Stepien, Hsien C. Yao
Life of this patent
Estimating the term…
Abstract
A catalyst system and method of making the same is taught for treating exhaust gases from an internal combustion engine. A catalyst system includes a substrate and a washcoat on the substrate. The washcoat is formed of zirconia. A catalyst is placed on the washcoat consisting of rhodium metal or rhodium metal with another catalyst metal. By using zirconia as a washcoat, the rhodium is not dissolved into the washcoat during periods when the catalyst system is subjected to high temperature oxidizing conditions, as is the case when a gamma alumina washcoat is used.
Claims2
A catalyst system which comprises:
- a substrate;
- a washcoat on said substrate, said washcoat consisting essentially of zirconia;
- and
- a catalyst on said washcoat, said catalyst consisting essentially of rhodium.
A method of reducing the migration of rhodium into a washcoat of a catalyst system which comprises the following steps:
- selecting a substrate;
- applying a washcoat on said substrate, said washcoat consisting essentially of zirconia;
- and
- applying a catalyst on said washcoat, said catalyst consisting essentially of rhodium.
Dependencies are inferred from the claim text.