Abstract: An emission control catalyst that exhibits improved CO and HC reduction performance includes supported precious group metal catalysts that are coated onto different layers of the substrate for the emission control catalyst. Zeolites of one or more types are added to the emission control catalyst as a hydrocarbon absorbing component to boost the low temperature performance of the emission control catalyst. Y zeolite is used by itself or mixed with other zeolites to enhance hydrocarbon storage at low temperatures.

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.

Abstract: A method for preparing a catalyst that involves continuously supplying a first stream containing a solvent, one or more metal precursors, and one or more support materials, and a second stream containing at least one reducing agent and/or precipitating agent. The first and second streams are combined to form a combined stream. In one embodiment, the combined stream may be fed to a mixing vessel. In another embodiment, the streams are combined in a mixing vessel. After the streams are combined, one or more metal precursors is reduced or precipitated within the pores of the one or more support materials. Thereafter, solids are separated from the combined stream and processed to produce the supported metal, mixed-metal, metal oxide, or mixed-metal oxide catalyst. In another embodiment, ceramic or metallic monoliths may be coated with the catalytic material after the stream combination and before or after the solid separation and subsequent processing.

Abstract: An engine exhaust catalyst exhibits improved CO oxidation performance relative to conventional engine exhaust catalysts and includes a first supported catalyst comprising platinum and a second supported catalyst comprising palladium and gold species in close contact. The first supported catalyst may be a platinum catalyst, a platinum—palladium catalyst, or a platinum catalyst promoted with bismuth, and the second supported catalyst preferably has a palladium to gold weight ratio of about 0.85:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones, or monoliths of the substrate for the engine exhaust catalyst.

Abstract: An emission control catalyst that exhibits improved CO and HC reduction performance includes supported precious group metal catalysts that are coated onto different layers of the substrate for the emission control catalyst. Zeolites of one or more types are added to the emission control catalyst as a hydrocarbon absorbing component to boost the low temperature performance of the emission control catalyst. Y zeolite is used by itself or mixed with other zeolites to enhance hydrocarbon storage at low temperatures.

Abstract: An engine exhaust catalyst containing precious metal nanoparticles is promoted with bismuth. The bismuth promotion improves the catalyst's CO oxidation performance. Also, by varying the amount of bismuth that is added, the NO conversion rate that can be realized with the catalyst can be controlled. The control over the NO conversion rate is important because the passive regenerative performance of a particulate filter used in engine exhaust systems is based on the amount NO2 that is present in the exhaust stream that reaches the particulate filter. The amount of NO2 being produced needs to be optimized (not necessarily maximized) so that adequate particulate filter regeneration performance can be maintained while avoiding unused, toxic NO2 from being exhausted into the atmosphere.

Abstract: An engine exhaust catalyst containing precious metal nanoparticles is promoted with bismuth. The bismuth promotion improves the catalyst's CO oxidation performance. Also, by varying the amount of bismuth that is added, the NO conversion rate that can be realized with the catalyst can be controlled. The control over the NO conversion rate is important because the passive regenerative performance of a particulate filter used in engine exhaust systems is based on the amount NO2 that is present in the exhaust stream that reaches the particulate filter. The amount of NO2 being produced needs to be optimized (not necessarily maximized) so that adequate particulate filter regeneration performance can be maintained while avoiding unused, toxic NO2 from being exhausted into the atmosphere.

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.

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.

Abstract: A multi-layer emission control catalyst exhibits improved CO and HC reduction performance. The bottom layer includes a supported catalyst comprising platinum and palladium particles or palladium and gold particles. The middle layer includes zeolites. The top layer includes a supported catalyst comprising platinum and palladium particles. The use of zeolite mixture in the middle layer further improves CO and HC reduction performance in comparison with using zeolite of a single type. The use of a supported catalyst comprising palladium and gold particles in the bottom layer further improves CO and HC reduction performance in comparison with using a supported catalyst comprising platinum and palladium particles.

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.

Abstract: An engine exhaust catalyst exhibits improved CO oxidation performance relative to conventional engine exhaust catalysts and includes a first supported catalyst comprising platinum and a second supported catalyst comprising palladium and gold species in close contact. The first supported catalyst may be a platinum catalyst, a platinum-palladium catalyst, or a platinum catalyst promoted with bismuth, and the second supported catalyst preferably has a palladium to gold weight ratio of about 0.85:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones, or monoliths of the substrate for the engine exhaust catalyst.

Abstract: A multi-layer emission control catalyst exhibits improved CO and HC reduction performance. The bottom layer includes a supported catalyst comprising platinum and palladium particles or palladium and gold particles. The middle layer includes zeolites. The top layer includes a supported catalyst comprising platinum and palladium particles. The use of zeolite mixture in the middle layer further improves CO and HC reduction performance in comparison with using zeolite of a single type. The use of a supported catalyst comprising palladium and gold particles in the bottom layer further improves CO and HC reduction performance in comparison with using a supported catalyst comprising platinum and palladium particles.

Abstract: An engine exhaust catalyst exhibits improved CO oxidation performance relative to conventional engine exhaust catalysts and includes a first supported catalyst comprising platinum and a second supported catalyst comprising palladium and gold species in close contact. The first supported catalyst may be a platinum catalyst, a platinum-palladium catalyst, or a platinum catalyst promoted with bismuth, and the second supported catalyst preferably has a palladium to gold weight ratio of about 0.85:1.0. To improve aged catalyst performance, the first and second supported catalysts are coated onto different layers, zones, or monoliths of the substrate for the engine exhaust catalyst.

Abstract: An engine exhaust catalyst containing precious metal nanoparticles is promoted with bismuth. The bismuth promotion improves the catalyst's CO oxidation performance. Also, by varying the amount of bismuth that is added, the NO conversion rate that can be realized with the catalyst can be controlled. The control over the NO conversion rate is important because the passive regenerative performance of a particulate filter used in engine exhaust systems is based on the amount NO2 that is present in the exhaust stream that reaches the particulate filter. The amount of NO2 being produced needs to be optimized (not necessarily maximized) so that adequate particulate filter regeneration performance can be maintained while avoiding unused, toxic NO2 from being exhausted into the atmosphere.