Abstract: A selective catalytic reduction (SCR) catalyst includes a support layer. A copper-loaded chabazite (Cu/CHA) layer is supported on the support layer. A copper-loaded beta zeolite (Cu/beta) is supported on the Cu/CHA layer. The Cu/beta may be hydrothermally pre-aged prior to use of the SCR catalyst in a vehicle. The pre-aged Cu/beta is essentially free of phosphorous (P), calcium (Ca), zinc (Zn), sodium (Na), potassium (K), magnesium (Mg), iron (Fe), CaSO4, Ca19Zn2(PO4)14, CaZn2(PO4)2, ash, and/or soot.

Abstract: A hydrocarbon and NOx trap and related apparatus and methods for reducing cold-start NOx emissions from an engine are provided. In one embodiment a trap includes a first, topmost layer, exposed to an exhaust gas flow path of exhaust gases from an engine, the first layer comprising a zeolite, a second layer, substantially covered by the topmost layer, the second layer comprising a NOx adsorbing material and a monolithic substrate, directly supporting the second layer and indirectly supporting the first layer, the substrate providing a substantially rigid structure of the trap. In this way, engine emissions, such as NOx and hydrocarbons may be adsorbed over the exhaust trap at low temperature and then thermally released, limiting cold start emissions beyond engines that only include a lean NOx trap.

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 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 method for controlling emissions from an engine includes reducing trapped nitrogen oxides to ammonia on an LNT catalyst while concurrently oxidizing soot accumulated on the LNT catalyst, and, flowing the ammonia so formed to an SCR catalyst.

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: 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.

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: 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: 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: 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 maintain the emission control devices below a maximum temperature.

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: Systems and methods are provided for reducing NOx emissions from a vehicle including an engine having an exhaust. In one example, the system comprises a NOx reducing system coupled to the engine exhaust including a base metal zeolite, said NOx reducing system including a first layer with a first pore size and a second layer with a second pore size, said first pore size being smaller than said second pore size.

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 system and method for NOx reduction is described, with a catalytic unit including a first zeolite catalyst with a first NOx conversion performance in a first temperature range and a second NOx conversion performance, lower than said first NOx conversion performance, in a second temperature range. The catalytic unit also comprises a second zeolite catalyst with a third NOx conversion performance, lower than said first NOx conversion performance, in the first temperature range and a fourth NOx conversion performance, higher than said second and third NOx conversion performances in the second temperature range, said first temperature range being higher than said second temperature range. The system further includes a controller configured to adjust an amount of reducing agent added to the NOx reducing system responsive to a temperature of the catalytic unit.

Abstract: A method for controlling emissions from an engine includes reducing trapped nitrogen oxides to ammonia on an LNT catalyst while concurrently oxidizing soot accumulated on the LNT catalyst, and, flowing the ammonia so formed to an SCR catalyst.

Abstract: Systems and methods are provided for reducing exhaust NOx species using a monolith substrate having a plurality of channels configured with radially varying cell density. An injector injects reductant into the substrate unobstructedly, without use of a mixer. In some embodiments, a twist angle of the channels is based on a distance from an inlet of the substrate and varies exponentially as a function of the distance.

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 system and method for NOx reduction is described, with a catalytic unit including a first zeolite catalyst with a first NOx conversion performance in a first temperature range and a second NOx conversion performance, lower than said first NOx conversion performance, in a second temperature range. The catalytic unit also comprises a second zeolite catalyst with a third NOx conversion performance, lower than said first NOx conversion performance, in the first temperature range and a fourth NOx conversion performance, higher than said second and third NOx conversion performances in the second temperature range, said first temperature range being higher than said second temperature range. The system further includes a controller configured to adjust an amount of reducing agent added to the NOx reducing system responsive to a temperature of the catalytic unit.

Abstract: A method of managing vapors generated from an ammonia-containing reductant delivery system for a vehicle is described. The method may include storing ammonia containing vapors generated in the reductant delivery system during engine-off and then purging said stored ammonia into an exhaust of the engine to react in a catalyst in the exhaust flow during engine operation.