Abstract: A catalyst system for reducing N2O emissions in the exhaust system of a vehicle is provided and comprises a support in communication with the exhaust gas stream, with the support including an exhaust gas inlet and an exhaust gas outlet. The support has at least one exhaust gas passage therethrough. The support, which may be in the form of a monolithic, multi-cell honeycomb construction, comprises a first catalytic zone and a second catalytic zone positioned downstream from the first zone. The first catalytic zone includes rhodium or a rhodium-enriched catalyst, while the second catalytic zone includes palladium or a palladium-enriched catalyst.

Abstract: Methods and systems are provided for exhaust heat recovery and hydrocarbon trapping at an exhaust bypass assembly. Exhaust gas may flow in both directions through an exhaust bypass passage and each of a HC trap and a heat exchanger coupled to the bypass passage. The HC trap may be purged with the hot exhaust and heat from the exhaust may be recovered at the heat exchanger.

Abstract: A particulate filter for use in a vehicle engine exhaust is provided which includes a catalyst containing a mixture of nickel and copper. The catalyst is impregnated into the filter substrate, which is non-reactive with nickel and copper. When used in a vehicle exhaust gas treatment system, the catalyst on the filter improves soot burn-off at low temperatures, provides improved efficiency in reducing CO and NOx emissions over the use of conventional three-way-catalyst washcoats, and provides enhanced oxygen storage capacity (OSC) and water-gas-shift (WGS) functions.

Abstract: A hydrocarbon trap catalyst and method of forming the same are disclosed. The method may include introducing copper into a zeolite at 10% to 75% of an ion-exchange level of the zeolite, introducing at least one of nickel and manganese into a zeolite at 50% to 100% total of an ion-exchange level of the zeolite, and applying a three-way catalyst layer. The copper and nickel and/or manganese may be introduced into a single zeolite or the copper may be introduced into a first zeolite layer and the nickel and/or manganese may be introduced into a second zeolite layer. If copper and another metal are introduced into the same zeolite, copper may be introduced first. The disclosed trap catalyst may increase the release temperature of hydrocarbons such as ethanol, propylene and toluene, and thus reduce vehicle cold start tailpipe emissions.

Abstract: A motor-vehicle engine system comprises a first DOC configured to receive exhaust from an engine and an SCR device coupled downstream of the first DOC in a flow direction of the exhaust. The system further comprises a second DOC coupled downstream of the SCR device. The system takes advantage of hydrocarbon sorption in the SCR catalyst that is a function of temperature to enable reduced hydrocarbon emissions via oxidation at the second DOC.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: A method for a vehicle comprises responsive to installation of a new exhaust particulate filter, doping fuel with an ash-producing additive, and combusting the doped fuel to produce ash, wherein the ash deposits as an ash coating on the new exhaust particulate filter. In this way, a filtration efficiency of an exhaust particulate filter can be increased quickly as compared to a filter with no deposited ash coating, inexpensively as compared to conventional methods using membranes, and with a lower back pressure drop as compared to conventional methods.

Abstract: Methods and systems are provided for improving engine exhaust emissions while enabling exhaust catalyst regeneration following an engine lean event. Prior to a VDE event, or prior to an engine idle-stop, ammonia is produced and stored on an exhaust underbody SCR catalyst. Then, during the engine restart after the VDE mode or the idle-stop, the stored ammonia is used to treat exhaust NOx species while an upstream exhaust underbody three-way catalyst is regenerated.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: A catalyst system for reducing N2O emissions in the exhaust system of a vehicle is provided and comprises a support in communication with the exhaust gas stream, with the support including an exhaust gas inlet and an exhaust gas outlet. The support has at least one exhaust gas passage therethrough. The support, which may be in the form of a monolithic, multi-cell honeycomb construction, comprises a first catalytic zone and a second catalytic zone positioned downstream from the first zone. The first catalytic zone includes rhodium or a rhodium-enriched catalyst, while the second catalytic zone includes palladium or a palladium-enriched catalyst.

Abstract: A method for treating engine exhaust. The method includes contacting an NOx exhaust with an upstream catalyst material coated onto a substrate and including copper or iron loaded in a first zeolite at an upstream loading of 0 to 3.5 g/l to convert the NOx exhaust in a first temperature range of 150° C. to 500° C. to a first NOx converted exhaust. The method further includes contacting the first NOx converted exhaust with a downstream catalyst material coated onto the substrate downstream of the upstream catalyst material and including copper or iron loaded in a second zeolite at a downstream loading of 1.5 to 9.5 g/l to convert the first NOx converted exhaust in a second temperature range of 450° C. to 700° C.

Abstract: Methods and systems for controlling and/or diagnosing an emission control system of a vehicle having a first SCR region upstream of a second SCR region are provided herein. One exemplary method includes, indicating degradation based on a first SCR region performance during a first condition; and indicating degradation based on a second SCR region performance during a second condition, the first condition different than the second condition. In this way, different levels of degradation among different SCR regions may be used to indicate emissions levels have increased above a threshold value, for example.

Abstract: A reverse flow hydrocarbon trap is provided that improves the conversion of hydrocarbons present in the exhaust gases of a vehicle to more environmentally benign compounds during cold engine starts. The trap includes a substrate having at least one exhaust gas passage therethrough, with the walls of the exhaust gas passage including a hydrocarbon trapping material and an oxidative catalyst. The substrate includes an inlet for hot exhaust gas from a vehicle engine and an outlet for the exhaust gas and further includes an inlet channel, an outlet channel, and an intermediate channel through which exhaust gas flows. The intermediate channel is oriented such that the flow of exhaust gas through the exhaust gas passage is reversed from the direction of flow in the inlet and outlet channels to improve the performance of the hydrocarbon trap.

Abstract: Embodiments for controlling exhaust air-fuel ratio are provided. In one example, an engine method comprises adjusting upstream exhaust air-fuel ratio to maintain a first emission control device at or below a threshold temperature, and when the upstream exhaust air-fuel ratio is below a threshold, injecting air into an exhaust passage between the first emission control device and a second emission control device to maintain downstream exhaust at a different, higher air-fuel ratio. In this way, excess emissions may be converted while maintaining the emission control devices below a maximum temperature.

Abstract: A reverse flow hydrocarbon trap is provided that improves the conversion of hydrocarbons present in the exhaust gases of a vehicle to more environmentally benign compounds during cold engine starts. The trap includes a substrate having at least one exhaust gas passage therethrough, with the walls of the exhaust gas passage including a hydrocarbon trapping material and an oxidative catalyst. The substrate includes an inlet for hot exhaust gas from a vehicle engine and an outlet for the exhaust gas and further includes an inlet channel, an outlet channel, and an intermediate channel through which exhaust gas flows. The intermediate channel is oriented such that the flow of exhaust gas through the exhaust gas passage is reversed from the direction of flow in the inlet and outlet channels to improve the performance of the hydrocarbon trap.

Abstract: A method for treating engine exhaust. The method includes contacting an NOx exhaust with an upstream catalyst material coated onto a substrate and including copper or iron loaded in a first zeolite at an upstream loading of 0 to 3.5 g/l to convert the NOx exhaust in a first temperature range of 150° C. to 500° C. to a first NOx converted exhaust. The method further includes contacting the first NOx converted exhaust with a downstream catalyst material coated onto the substrate downstream of the upstream catalyst material and including copper or iron loaded in a second zeolite at a downstream loading of 1.5 to 9.5 g/l to convert the first NOx converted exhaust in a second temperature range of 450° C. to 700° C.

Abstract: Embodiments for controlling exhaust oxygen concentration are provided. In one example, an engine method comprises operating the engine with lean combustion, and when exhaust oxygen concentration is below a threshold, injecting air into an exhaust passage between a first emission control device and an SCR device. In this way, excess emissions may be converted while operating with lean combustion.

Abstract: According to one aspect of the present invention, a catalyst assembly is provided for treating an exhaust from an engine. In one embodiment, the catalyst assembly includes a first catalyst material catalytically active at a first temperature and loaded at a first catalyst material loading, the first catalyst material including a first base metal loading, and a second catalyst material catalytically active at a second temperature lower than the first temperature and loaded at a second catalyst material loading, the second catalyst material including a second base metal loading, wherein the second base metal loading is higher than the first base metal loading.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: In one embodiment, a method for an engine comprises operating the engine with an upstream exhaust sensor, intermediate exhaust sensor, and downstream exhaust sensor each indicating rich, adjusting engine operation to operate the engine with an upstream exhaust sensor, intermediate exhaust sensor, and downstream exhaust sensor each indicating lean, adjusting engine operation to operate the engine with the upstream exhaust sensor indicating rich and the intermediate and downstream exhaust sensors each indicating lean, and indicating degradation of an SCR catalyst based on when the intermediate and downstream exhaust sensors switch from lean to rich.