Methods and systems are provided for reducing emissions during an engine cold start. In one example, a method may include, during emission control device heating, injecting heated air into an exhaust runner of each cylinder of the engine during an exhaust stroke of the corresponding cylinder, after a blowdown exhaust pulse. In this way, an amount of hydrocarbons in feedgas provided to the emission control device prior to the emission control device reaching its light-off temperature may be reduced.

The present invention is directed at the integration of a solid oxide fuel cell (SOFC) into the exhaust stream of an internal combustion engine aided by the upstream injection of a fuel, such as a hydrocarbon fuel. The internal combustion engine may be advantageously operated in a lean condition while the SOFC receives the hydrocarbon fuel to promote and maintain optimized fuel cell operation.

An exhaust treatment system includes an exhaust line, a series of emission treatment units, and an electronic control unit. The series of emission treatment units includes a catalytic unit, a particulate filter unit, an oxidation catalytic unit, a hydrogen injection unit, and a Lean NOx Trap (LNT) for trapping select emissions. A method of operating an exhaust treatment system includes introducing a fuel to a combustion engine of a motor vehicle, directing emissions from the combustion engine to an exhaust line, and passing the emissions in the exhaust line through a series of emission treatment units on the exhaust line. The method further includes injecting hydrogen into the exhaust line via a hydrogen injection unit, where an amount of hydrogen gas injected from a hydrogen inlet line reduces the trapped emissions in the LNT to an inert gas.

Disclosed herein are emission treatment systems, articles, and methods for selectively reducing NOx compounds. The systems include a hydrogen generator, a hydrogen selective catalytic reduction (H.sub.2-SCR) article, and one or more of a diesel oxidation catalyst (DOC) and/or a lean NOx trap (LNT) and/or a low temperature NOx adsorber (LTNA). Certain articles may comprise a zone coated substrate and/or a layered coated substrate and/or an intermingled coated substrate of one or more of the H.sub.2-SCR and/or DOC and/or LNT and/or LTNA catalytic compositions.

The disclosure provides a platinum-containing three-way conversion (TWC) catalyst, and a system for treating an exhaust gas stream from a gasoline engine using the TWC catalyst. The system is configured to introduce controlled quantities of hydrogen gas into the exhaust gas stream upstream of the platinum-containing TWC catalyst article during a cold-start period. Further provided are related methods of treating such exhaust streams. Such systems and methods are useful in reducing a level of one or more of hydrocarbons, carbon monoxide, and nitrogen oxide in a gaseous exhaust stream from a gasoline engine.

A system, apparatus, and method for oxidizing methane in the exhaust gas from a lean-burn combustion gas engine in which a syngas stream comprising H.sub.2 and CO, or a combustible hydrocarbon with a light-off temperature at or below the temperature of the engine exhaust temperature, is added to and combined with the engine exhaust stream and passed through an oxidation catalyst whereupon the combustible gas oxidizes and increases the operating temperature of a platinum group oxidation catalyst sufficiently to exceed the light-off temperature of the platinum group catalyst for oxidizing methane emissions contained in the engine exhaust stream.

Systems and methods for treating automotive vehicle emissions on board an automotive vehicle include the use of waste heat recovery, electrochemical water splitting, phototcatalytic water splitting, and selective catalytic reduction. Waste heat recovery is used to power electrochemical water splitting, or photocatalytic water splitting. Photons collected from a solar panel are used in photocatalytic water splitting, or in photo-assisted selective catalytic reduction. Hydrogen gas generated by water splitting is used in conjunction with catalytic reduction units to catalytically reduce NOx in an engine exhaust gas.

Exhaust gas is treated onboard a vehicle. Solar energy is converted into electricity, which is used to power an electrochemical cell mounted onboard the vehicle. Oxygen and hydrogen are produced by the electrochemical cell. Heat and the oxygen produced by the electrochemical cell are provided to a particulate matter filter onboard the vehicle, thereby oxidizing particulate matter disposed on the particulate matter filter.

A system, apparatus, and method for oxidizing methane in the exhaust gas from a lean-burn combustion gas engine in which a syngas stream comprising H.sub.2 and CO, or a combustible hydrocarbon with a light-off temperature at or below the temperature of the engine exhaust temperature, is added to and combined with the engine exhaust stream and passed through an oxidation catalyst whereupon the combustible gas oxidizes and increases the operating temperature of a platinum group oxidation catalyst sufficiently to exceed the light-off temperature of the platinum group catalyst for oxidizing methane emissions contained in the engine exhaust stream.

The invention provides an emission control system for treatment of an exhaust gas stream that includes an oxidation catalyst composition disposed on a substrate in fluid communication with the exhaust gas stream; at least one selective catalytic reduction (SCR) composition disposed on a substrate downstream from the oxidation catalyst composition, and a hydrogen injection article configured to introduce hydrogen into the exhaust gas stream upstream of the oxidation catalyst composition or downstream of the oxidation catalyst composition and upstream of the at least one SCR composition. The invention also provides a method of treating an exhaust gas stream, the method including receiving the exhaust gas stream into the emission control system of the invention and intermittently introducing hydrogen upstream of the oxidation catalyst article or downstream of the oxidation catalyst article and upstream stream of the SCR article.