Gm Global Technolgoy Operations, Inc.

Basf Corporation

Steven Jeffrey Schmieg

Chang H Kim

Wei Ping Li

Gongshin Qi

Eugene Victor Gonze

Michael J Paratore, Jr

David Brian Brown

Michael B Viola

Se Hyuck Oh

Byong Kwon Cho

Shouxian Ren

Kevin L Perry

Shi-Wai S Cheng

Thompson M Sloane

Calvin K Koch

Jong H Lee

Jong-Hwan Lee

Richard J Blint

David L Hilden

Patricia A Mulawa

Paul M Najt

Ahmad Moini

Rahul Mital

Janean Kowalkowski

Gerald Stephen Koermer

Jianwen Li

Kushal Narayanaswamy

Karthik Ramanathan

Thomas J Chapaton

Christopher R Castellano

David N Belton

Howard Furbeck

Ashok Gopinath

Kenneth B Gross

Daniel Dziedzic

Jerome P Ortmann

Ling Deng

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/AlO) 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. The monolith is located near the exhaust manifold of the lean burn engine where the combination of NOx adsorber particles temporarily adsorb exhaust constituents, and commence oxidation of them, until the progressively warming exhaust stream removes the stored constituents and carries them through the exhaust pipe to downstream NOx reduction converters which have been heated to their operating temperatures and complete the conversion of the NOx constituents to nitrogen and water for discharge from the vehicle's exhaust system.

Synergistic combinations of low temperature NOx adsorbers

A SCR device includes a substrate having a first portion, and a second portion disposed downstream of the first portion. The first portion of the substrate includes a volume that is between 15% and 25% of a total volume of the substrate. A first selective catalytic reduction compound is disposed on the first portion of the substrate, and includes an iron zeolite (Fe-Zeolite) compound. A second selective catalytic reduction compound is disposed on the second portion of the substrate, and includes a copper (Cu) SAPO-34 compound. The copper SAPO-34 compound includes a catalyst density of less than 2.74 mg copper per cubic centimeter of copper SAPO-34 compound. The copper SAPO-34 compound is applied onto the second portion of the substrate at a compound density of less than 110 g of copper SAPO-34 compound per liter of volume of the second portion of the substrate.

Selective catalytic reduction device

A method for removing NOfrom an oxygen-rich exhaust flow produced by a combustion source that is combusting a lean mixture of air and fuel may include passing the oxygen-rich exhaust flow through an exhaust aftertreatment system that includes a NOoxidation catalyst that includes perovskite oxide particles, a NOstorage catalyst, and a NOreduction catalyst.

Perovskite oxide compounds for use in exhaust aftertreatment systems

An aftertreatment system utilizes chemical reactions to treat an exhaust gas flow. A device for use within an aftertreatment system includes a silver-based NOx storage catalyst and a zeolite. The silver-based NOx storage catalyst and the zeolite store NOx through a low temperature startup period of operation. In one embodiment, the zeolite includes a barium Y zeolite.

Zeolite promoted silver based catalyst for NOx storage

A method of treating an exhaust gas produced by a vehicle internal combustion engine includes conveying the gas through a first reactor including a non-thermal plasma. The gas includes nitric oxide and is transitionable between a first condition in which the gas has a cold-start temperature that is less than or equal to about 150&#xb0; C., and a second condition in which the gas has an operating temperature that is greater than about 150&#xb0; C. During the first condition, the method includes contacting the gas and plasma to oxidize the nitric oxide to nitrogen dioxide and form an effluent that includes nitrogen dioxide. The method includes concurrently conveying the effluent through a second reactor including a diesel oxidation catalyst, and storing the nitrogen dioxide within the second reactor during only the first condition. The method includes, after storing, releasing nitrogen dioxide from the second reactor during only the second condition.

Vehicle and method of treating an exhaust gas

The capacity of a platinum-containing diesel oxidation catalyst (DOC) to simultaneously convert NO to NO, CO to carbon dioxide, and remaining hydrocarbons to carbon dioxide and water in the exhaust system of a vehicle diesel engine may be evaluated and diagnosed using measured DOC exhaust inlet temperatures and outlet temperatures at a relatively high exhaust temperature and, soon thereafter, at a relatively low exhaust inlet temperature. Values of the platinum-containing DOC exotherms at the high and low DOC inlet temperatures are found to provide a basis for evaluation of both NO conversion and the HC and CO conversion capabilities of the DOC. The process may be repeated as the catalyzed DOC conversion efficiency changes with use. The practice may also be used to evaluate the performance of oxidation catalysts used in a like way in treating the exhaust from a lean-burn gasoline engine.

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Following a cold start of a hydrocarbon-fueled engine operated in a lean-burn-combustion mode, several seconds and minutes may be required for the exhaust gas stream to heat exhaust treatment devices in the exhaust system and conduit to their effective operating temperatures. The warm-up period may be particularly long for a NOx reduction catalyst (SCR) located downstream in the exhaust flow system. Accordingly, a bed of absorbent material, such as a suitably sized bed of alumina particles, located upstream of the SCR, is used to temporarily absorb water and NOx from a relatively cold exhaust until the exhaust has suitably heated the SCR to its operating temperature. Then, the warmed exhaust will remove the water and NOx from their temporary storage material and carry them to the reduction catalyst.

Low temperature NOx storage system for lean exhaust aftertreatment

One embodiment of the invention may include a method comprising providing a product comprising a substrate comprising a perovskite catalyst, NOstored in or on the substrate and particulate matter in or on the substrate; releasing at least some of the stored NOand oxidizing the released NOx to form NO, and reacting the NOwith carbon in the particulate matter to form at least one of CO or CO.

Perovskite-based catalysts, catalyst combinations and methods of making and using the same

Ag/AlOmaterials may be packaged in a suitable flow-through reactor, in combination with another material selected as a passive NOx adsorber material (PNA), both the silver material and the adsorber material being close coupled to the exhaust manifold of a diesel engine, and upstream of other catalytic devices, such as a diesel oxidation catalyst and a selective reduction catalyst for NOx. The silver catalyst material uses hydrogen in a cold-start engine exhaust and serves to oxidize NO to NOin the relatively low temperature, hydrocarbon-containing, exhaust during a short period following the engine cold start, and to temporarily store NOx during the start-up period. After the flowing exhaust gas stream has heated the PNA and the downstream catalytic devices, the silver yields its nitrogen oxides for conversion to nitrogen by the then-operating devices before NOx is discharged to the atmosphere.

Silver promoted close-coupled NOx absorber

Ag/AlOmaterials may be packaged in a suitable flow-through reactor, close coupled to the exhaust manifold of a diesel engine, and upstream of other exhaust gas treatment devices, such as a diesel oxidation catalyst and a selective reduction catalyst for NOx. The silver/alumina catalyst material uses hydrogen in a cold-start engine exhaust and serves to oxidize NO to NOin the relatively low temperature, hydrocarbon-containing, exhaust during a short period following the engine cold start, and to temporarily store NOx during the start-up period. After the exhaust has heated downstream catalytic devices, the silver yields its nitrogen oxides for conversion to nitrogen by the then-operating devices before NOx is discharged to the atmosphere.

Nitric oxide oxidation over silver-based catalysts

An exhaust gas treatment system for an internal combustion engine is provided, including an exhaust gas conduit, a flow-through container of absorbent particles, an electrically heated catalyst ('EHC') device, a selective catalytic reduction ('SCR') device, and a control module. The exhaust gas conduit is in fluid communication with, and is configured to receive an exhaust gas from the internal combustion engine. The exhaust gas contains oxides of nitrogen (&#x201c;NO&#x201d;) and water. The flow-through container of absorbent particles is in fluid communication with the exhaust gas conduit and configured to receive the exhaust gas. The flow-through container substantially adsorbs the water from the exhaust gas below a threshold temperature. The EHC device is in fluid communication with the exhaust gas conduit and is configured to receive the exhaust gas. The EHC device is located downstream of the flow through container, and is selectively activated to produce heat.

Selective catalytic reduction (SCR) system for NOx storage

A cold start NOgeneration system includes a catalyst control module that identifies a portion of a three-way catalyst that corresponds to a nitrogen dioxide zone. A diagnostic module determines a temperature in the nitrogen dioxide zone, and a fuel control module adjusts an air/fuel ratio based on the temperature in the nitrogen dioxide zone. A cold start NOgeneration method includes identifying a portion of a three-way catalyst that corresponds to a nitrogen dioxide zone. The method further includes determining a temperature in the nitrogen dioxide zone and adjusting an air/fuel ratio based on the temperature in the nitrogen dioxide zone.

A method for monitoring a hydrocarbon-selective catalytic reactor device of an exhaust aftertreatment system of an internal combustion engine operating lean of stoichiometry includes injecting a reductant into an exhaust gas feedstream upstream of the hydrocarbon-selective catalytic reactor device at a predetermined mass flowrate of the reductant, and determining a space velocity associated with a predetermined forward portion of the hydrocarbon-selective catalytic reactor device. When the space velocity exceeds a predetermined threshold space velocity, a temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is determined, and a threshold temperature as a function of the space velocity and the mass flowrate of the reductant is determined. If the temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is below the threshold temperature, operation of the engine is controlled to regenerate the hydrocarbon-selective catalytic reactor device.

Method and apparatus for monitoring a hydrocarbon-selective catalytic reduction device

A low-oxygen content exhaust flow produced by an engine that is combusting, on average, a stoichiometric mixture of air and fuel generally contains various unwanted gaseous emissions. The exhaust flow is treated by an exhaust aftertreatment system that includes a three-way-catalyst (TWC) and an ammonia-selective catalytic reduction (ammonia-SCR) catalyst positioned downstream from the TWC in a flow direction of the exhaust flow. The ammonia-SCR catalyst includes (1) a base metal ion-substituted zeolite and/or a base metal ion-substituted silicoaluminophosphate and (2) an oxygen storage material selected from the group consisting of a metal oxide or a mixed metal oxide that exhibits oxygen storage and release capacity. The serial arrangement of the TWC and the ammonia-SCR catalyst enhances the conversion of NOto Nin the low oxygen-content exhaust flow produced by the engine and helps prevent ammonia slip to the atmosphere.

Exhaust aftertreatment systems that include an ammonia-SCR catalyst promoted with an oxygen storage material

An exhaust gas treatment system for an internal combustion engine is provided having an exhaust gas conduit, an oxidation catalyst ('OC') device, a selective catalytic reduction ('SCR') device, and a control module. The internal combustion engine has at least one operating parameter. The exhaust gas conduit is in fluid communication with, and is configured to receive an exhaust gas from the internal combustion engine. The exhaust gas contains oxides of nitrogen (&#x201c;NO&#x201d;) and hydrocarbons. The exhaust gas has an exhaust gas temperature. The OC device is in fluid communication with the exhaust gas conduit, and is activated to induce oxidation of the hydrocarbons in the exhaust gas. The OC device has an oxidation catalyst compound disposed thereon that is selectively activated at a specified temperature range for converting nitrogen oxide (&#x201c;NO&#x201d;) to nitrogen dioxide (&#x201c;NO&#x201d;) at a specified percentage.

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Troy, MI, United States of America

Steven Jeffrey Schmieg