Engine exhaust catalysts containing palladium-gold
AssigneeNanostellar, Inc.
InventorsKyle L. Fujdala, Timothy J. Truex, Jifei Jia
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Abstract
An emission control catalyst that exhibits improved CO and HC reduction performance includes a supported platinum-based catalyst, and a supported palladium-gold catalyst. The two catalysts are coated onto different layers, zones, or monoliths of the substrate for the emission control catalyst such that the platinum-based catalyst encounters the exhaust stream before the palladium-gold catalyst. Zeolite may be added to the emission control catalyst as a hydrocarbon absorbing component to boost the oxidation activity of the palladium-gold catalyst.
Claims20
An emission control catalyst for treating an engine exhaust comprising a first zone and a second zone, the first zone including a first supported catalyst comprising platinum-containing metal particles supported on an oxide carrier and the second zone including a second supported catalyst consisting essentially of palladium-gold metal particles supported on an oxide carrier, wherein the second supported catalyst has a palladium to gold weight ratio range of about 0.5:1 to about 1:0.5.
An emission control catalyst for treating an engine exhaust comprising a monolith having an upstream zone and a downstream zone, the upstream zone including a first supported catalyst comprising platinum-containing metal particles supported on an oxide carrier and the downstream zone including a second supported catalyst consisting essentially of palladium-gold metal particles supported on an oxide carrier, wherein the upstream zone is positioned to encounter the engine exhaust before the downstream zone.
An emission control catalyst for treating an engine exhaust comprising a first monolith and a second monolith, the first monolith including a first supported catalyst comprising platinum-containing metal particles supported on an oxide carrier and the second monolith including a second supported catalyst consisting essentially of palladium-gold metal particles supported on an oxide carrier, wherein the first monolith is positioned to encounter the engine exhaust before the second monolith.
Dependencies are inferred from the claim text.