Abstract: A nitrogen oxides (NOx) and hydrocarbon (HC) storage catalyst for treating an exhaust gas flow is provided. The NOx and HC storage catalyst includes (a) a zeolite, (b) noble metal atoms, and (c) a metal oxide, a non-metal oxide, or a combination thereof. One or more of the noble metal atoms is present in a complex with the metal oxide, the non-metal oxide or a combination thereof. The complex is dispersed within a cage of the zeolite. Methods of preparing the NOx and HC storage catalyst and methods of using the NOx and HC storage catalyst for treating an exhaust gas stream flowing from a vehicle internal combustion engine during a period following a cold-start of the engine are also provided.

Abstract: According to one or more embodiments described herein, an exhaust system for treating exhaust gas from an internal combustion engine in a motor vehicle includes a passive NOx absorber (PNA) device, and a model-based controller that controls an amount of NOx stored by the PNA device. Controlling of the amount of NOx stored includes computing a predicted NOx storage level of the PNA device using a prediction model of the PNA device, and in response to the predicted NOx storage level of the PNA device being greater than a predetermined cold-start threshold, raising a temperature of the exhaust gas by changing an operation of the internal combustion engine.

Abstract: Internal combustion engine (ICE) exhaust gas treatment systems include the ICE having one or more cylinders configured to receive a mixture of air and fuel defined by an air to fuel ratio (AFR) for combustion therein, a control module configured to control the AFR, a diesel oxidation catalyst (DOC) configured to receive exhaust gas generated by the ICE and oxidize NOx species within the exhaust gas, and a selective catalytic reduction device (SCR) configured to receive exhaust gas from the DOC. Methods for operating and diagnosing such systems include determining, via the control module, a baseline value of a SCR performance parameter which is unsuitable, changing, via the control module, the AFR to change the DOC outlet NO2:NOx ratio, subsequently assessing a second value of the SCR performance parameter, and implementing a control action based on the second value of the SCR performance parameter.

Abstract: Internal combustion engine (ICE) exhaust gas treatment systems include the ICE having one or more cylinders configured to receive a mixture of air and fuel defined by an air to fuel ratio (AFR) for combustion therein, a control module configured to control the AFR, a diesel oxidation catalyst (DOC) configured to receive exhaust gas generated by the ICE and oxidize NOx species within the exhaust gas, and a selective catalytic reduction device (SCR) configured to receive exhaust gas from the DOC. Methods for operating and diagnosing such systems include determining, via the control module, a baseline value of a SCR performance parameter which is unsuitable, changing, via the control module, the AFR to change the DOC outlet NO2:NOx ratio, subsequently assessing a second value of the SCR performance parameter, and implementing a control action based on the second value of the SCR performance parameter.

Abstract: Provided are methods for diagnosing a selective catalytic reduction device (SCR) of an exhaust gas treatment system, wherein the system includes an engine, an ammonia-generating catalytic device (AGC) configured to receive exhaust gas generated by the engine and capable of generating ammonia from rich exhaust gas, the SCR configured to receive exhaust gas and ammonia generated by the AGC, an upstream NOx sensor disposed upstream from the SCR, and a downstream NOx sensor disposed downstream from the SCR. The method includes increasing the temperature of the SCR to substantially empty all reductant stored within the SCR, during a diagnostic period, maintaining a rich engine operating condition and communicating the generated exhaust gas to the AGC and the SCR, determining a SCR reductant storage capacity based on measurements taken by the downstream NOx sensor during the diagnostic period, and optionally implementing a control action based on the determined storage capacity.

Abstract: According to one or more embodiments described herein, an exhaust system for treating exhaust gas from an internal combustion engine in a motor vehicle includes a passive NOx absorber (PNA) device, and a model-based controller that controls an amount of NOx stored by the PNA device. Controlling of the amount of NOx stored includes computing a predicted NOx storage level of the PNA device using a prediction model of the PNA device, and in response to the predicted NOx storage level of the PNA device being greater than a predetermined cold-start threshold, raising a temperature of the exhaust gas by changing an operation of the internal combustion engine.

Abstract: A selective catalytic reduction filter (SCRF) including a wall-flow substrate having inlet channels and outlet channels is provided. A first selective catalytic reduction (SCR) catalyst zone is present in the inlet channels, and a second SCR catalyst zone is present in the outlet channels. The first SCR catalyst zone includes an iron-exchanged zeolite catalyst, and the second SCR catalyst zone includes a copper-exchanged zeolite catalyst. Exhaust gas treatment systems including the SCRF and methods of reducing production of nitrous oxide (N2O) during selective catalytic reduction of an exhaust gas stream using the SCRF are also provided herein.

Abstract: A nitrogen oxides (NOx) and hydrocarbon (HC) storage catalyst for treating an exhaust gas flow is provided. The NOx and HC storage catalyst includes (a) a zeolite, (b) noble metal atoms, and (c) a metal oxide, a non-metal oxide, or a combination thereof. One or more of the noble metal atoms is present in a complex with the metal oxide, the non-metal oxide or a combination thereof. The complex is dispersed within a cage of the zeolite. Methods of preparing the NOx and HC storage catalyst and methods of using the NOx and HC storage catalyst for treating an exhaust gas stream flowing from a vehicle internal combustion engine during a period following a cold-start of the engine are also provided.

Abstract: A nitrogen oxides (NOx) storage catalyst for treating an exhaust gas flow is provided. The NOX storage catalyst includes a flow-through substrate defining channels for receiving the exhaust gas flow and first and second zones present in the channels. The first zone includes a first NOX storage catalyst coating capable of storing NOX at a first adsorption temperature and releasing NOX at a first desorption temperature. The second zone includes a second NOX storage catalyst coating capable of storing NOX at a second adsorption temperature and releasing NOX at a second desorption temperature. The second desorption temperature is greater than the first desorption temperature. Methods of using the NOX storage catalyst for treating an exhaust gas stream flowing from a vehicle engine during a period following a cold-start of the engine are also provided.

Abstract: A method for monitoring and diagnosing an engine exhaust treatment of an internal combustion engine in a motor vehicle includes monitoring a nitrogen oxides (NOx) storage catalyst disposed in an engine exhaust stream downstream of the engine, determining a first diagnostic condition of the NOx storage catalyst based on data from a first EGT sensor and a second EGT sensor; determining a second diagnostic condition of the NOx storage catalyst based on a comparison of temperatures reported by a first NOx sensor and a second NOx sensor, selectively pausing the first diagnostic condition and the second diagnostic condition during a predetermined NOx storage catalyst regeneration period, and selectively generating a notification for an operator of the motor vehicle.

Abstract: A selective catalytic reduction filter (SCRF) including a wall-flow substrate having inlet channels and outlet channels is provided. A first selective catalytic reduction (SCR) catalyst zone is present in the inlet channels, and a second SCR catalyst zone is present in the outlet channels. The first SCR catalyst zone includes an iron-exchanged zeolite catalyst, and the second SCR catalyst zone includes a copper-exchanged zeolite catalyst. Exhaust gas treatment systems including the SCRF and methods of reducing production of nitrous oxide (N2O) during selective catalytic reduction of an exhaust gas stream using the SCRF are also provided herein.

Abstract: A method for monitoring and diagnosing an engine exhaust treatment of an internal combustion engine in a motor vehicle includes monitoring a nitrogen oxides (NOx) storage catalyst disposed in an engine exhaust stream downstream of the engine, determining a first diagnostic condition of the NOx storage catalyst based on data from a first EGT sensor and a second EGT sensor; determining a second diagnostic condition of the NOx storage catalyst based on a comparison of temperatures reported by a first NOx sensor and a second NOx sensor, selectively pausing the first diagnostic condition and the second diagnostic condition during a predetermined NOx storage catalyst regeneration period, and selectively generating a notification for an operator of the motor vehicle.

Abstract: Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

Abstract: Technical solutions are described for limiting exposure of components of an emissions control system to rich exhaust conditions. An example an emissions control system includes an oxygen storage component; and a controller that limits exposure of the oxygen storage component to rich exhaust conditions. The limiting includes determining an air-to-fuel equivalence ratio in exhaust gas in response to an engine receiving a request to generate torque, the request including a displacement of a pedal; determining an amount of oxygen in the exhaust gas based on the air-to-fuel equivalence ratio; determining an oxygen level stored by the oxygen storage component; and if the oxygen level is above a predetermined threshold, lowering a torque generation rate of the engine, which specifies amount of torque generated per unit displacement of the pedal.

Abstract: An after-treatment (AT) system used to treat an exhaust gas flow emitted by an internal combustion engine includes a catalyst monolith configured to actively remove a pollutant from the exhaust gas flow. The AT system also includes a heating element configured to heat the catalyst monolith. The AT system additionally includes an energy-discharge unit configured to power the heating element. The energy-discharge unit includes an energy-storage device configured to supply electrical energy. The energy-discharge unit also includes a capacitor configured to receive the electrical energy from the energy-storage device and discharge the received electrical energy to power the heating element and thereby heat the catalyst monolith. A vehicle having an internal combustion engine operatively connected to such an AT system is also contemplated.

Abstract: Nitrogen oxides (NOx), carbon monoxide (CO), and residual hydrocarbons are adsorbed and stored from a low temperature, cold-start, diesel engine (or lean-burn gasoline engine) exhaust stream by a combination of a silver-based (Ag/Al2O3) NOx adsorber material and a zeolite-platinum group metal (zeolite-PGM) adsorber material for low temperature temporary storage of the NOx. The combination of NOx adsorber materials is formed as separate washcoats on channel walls of an extruded flow-through monolithic support.

Abstract: An after-treatment (AT) system used to treat an exhaust gas flow emitted by an internal combustion engine includes a catalyst monolith configured to actively remove a pollutant from the exhaust gas flow. The AT system also includes a heating element configured to heat the catalyst monolith. The AT system additionally includes an energy-discharge unit configured to power the heating element. The energy-discharge unit includes an energy-storage device configured to supply electrical energy. The energy-discharge unit also includes a capacitor configured to receive the electrical energy from the energy-storage device and discharge the received electrical energy to power the heating element and thereby heat the catalyst monolith. A vehicle having an internal combustion engine operatively connected to such an AT system is also contemplated.

Abstract: A vehicle includes a NOx storage converter to receive exhaust gases from a diesel engine, store at least a minimum amount of the NOx at a temperature below a storage threshold, release the NOx at a temperature above a releasing threshold, oxidize hydrocarbon, and oxidize carbon monoxide. An input temperature sensor at an entrance to the NOx storage converter determines an input temperature of the exhaust gases. An output temperature sensor is at an output of the NOx storage converter to determine an output temperature of the exhaust gases. A control module receives the input temperature and the output temperature, determines a magnitude of an exotherm in the NOx storage converter, and stores an electronic fault code in a computer memory in response to the magnitude of the exotherm being below a minimum temperature. The fault code indicates a reduction in a NOx storage capacity of the NOx storage converter.

Abstract: A method is disclosed of providing a fuel efficient regeneration of an exhaust after-treatment (AT) system that includes a lean oxides of nitrogen (NOX) trap (LNT) and a selective catalytic reduction filter (SCRF) positioned downstream of the LNT. The method includes regulating a selectable position valve. The valve permits a first gas flow portion to pass through the LNT and diverts a remaining second portion of exhaust gas flow from a first passage connecting an engine and the AT system to a second exhaust passage to thereby bypass the LNT. The method also includes regulating a first device to inject fuel into the first portion of the exhaust gas flow. The injection of fuel in to the first portion of the exhaust gas flow provides fuel efficient regeneration of the LNT and promotes NOX conversion and ammonia (NH3) formation in the LNT. A system employing the method is also disclosed.

Abstract: A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NOx when the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NOx when the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NOx. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NOx emissions from a diesel engine, the NOx emissions including NOx emitted during a predetermined cold-start time period.