Back to results
US 5,672,557 AGranted
Paladium-containing three-way automotive catalysts having unique support
AssigneeASEC Manufacturing
InventorsW. Burton Williamson, Ronald G. Silver, Jack C. Summers
Life of this patent
Estimating the term…
Abstract
A palladium three-way catalyst is supported on a unique ceria-lanthana-alumina support where the alumina content is lower than previously believed necessary to maintain catalyst activity. Preferably the ceria and lanthana constitute the major proportion of the support.
Claims8
A catalyst for reducing the amount of carbon monoxide, hydrocarbons, and nitrogen oxides in the exhaust gases from internal combustion engines comprising:
- (a) a support disposed on a monolithic substrate, said support consisting essentially of alumina, ceria and lanthana and, optionally, from 5-20 wt percent of a promoter, and
- (b) a catalytically effective amount between about 0.05 to 5.0 wt. % based on the total weight of the catalyst of palladium disposed on the support of (a);
- wherein the amount of cerium and lanthanum metals in the support is from about 80 g/L to about 300 g/L weight at a ratio of Ce to La of from 0.3/1 to 10/1;
- wherein the amount of alumina in the support constitutes less than 50 weight percent of the support and is less than about 100 g/L;
- and
- wherein the weight ratio of Ce plus La to alumina in the support is greater than about 3.
3 more elements
Dependencies are inferred from the claim text.