An exhaust system for an internal combustion engine (28) for controlling the release of undesirable emissions from the engine comprises an exhaust pipe (32) for receiving an exhaust flow from the engine, an SCR catalyst (48) arranged in the exhaust flow and means (80) for determining the temperature of the SCR catalyst. A NOx absorber (38), such as a diesel oxidation and NOx absorber catalyst (DONAC), is located in the exhaust flow at a position upstream of the SCR catalyst (48) for absorbing and releasing NOx contained in the exhaust flow. Means is provided for controlling the NOx absorber (38) so as to control the release of NOx to the SCR catalyst (48) in dependence on the temperature of the SCR catalyst, thereby to effect active management of release of NOx from the DONAC (38).

Systems and methods are provided for managing low temperature NO.sub.x and HC emissions, such as during a cold start of an internal combustion engine. The systems and methods include storing NO.sub.x and HC emissions at low temperatures and passively releasing and treating these emissions as the temperature of the exhaust system increases.

A device for reducing emissions from an internal combustion engine having a close-coupled catalyst including an electrically-heated catalyst and a hydrocarbon trap disposed downstream of the close-coupled catalyst. The device includes a heat exchanger and a liquid water knockout disposed downstream of the close-coupled catalyst. The device includes a valve-less system configured to dynamically adjust a flow path of exhaust from the internal combustion engine through the electrically-heated catalyst and the hydrocarbon trap to reduce emissions. A method for reducing emissions including feeding an exhaust gas from the internal combustion engine to the close-coupled catalyst, producing a catalyzed exhaust gas. The method includes flowing the catalyzed exhaust gas from the close-coupled catalyst to the valve-less system.

A heat exchanger system for treatment of a flow of exhaust gases in an exhaust gas aftertreatment system of a vehicle. The heat exchanger system includes a nitrogen monoxide (NO) oxidation site for oxidising nitrogenmonoxide to nitrogen dioxide (NO2). The NO oxidation site is positioned such that the flow of exhaust gases at a downstream end (40) of the NO oxidation site in use of the heat exchanger system is arranged to proceed at a temperature within a predetermined temperature interval corresponding to a desired NO to NO2(NO:NO2) ratio interval in the flow of exhaust gases. An exhaust gas aftertreatment system and a vehicle including such a heat exchanger system, and a method for using such a heat exchanger system, are also provided.

A method and apparatus for reducing at least one of HC, CO, and NO.sub.x emissions from an operating internal combustion engine fueled by hydrocarbon or similar fuels, such as alcohols, wherein a portion of the internal combustion chamber has aluminum and/or titanium containing surfaces coated with a titanium dioxide coating further comprising a dopant in and/or on the adherent titanium dioxide coating.

An oxidation catalyst for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a first washcoat region comprising a first platinum group metal (PGM), a first support material and a NO.sub.x storage component; a second washcoat region comprising platinum (Pt), manganese (Mn) and a second support material; and a substrate having an inlet end and an outlet end.

A control device for an internal combustion engine is provided. The control device includes an electronic control unit. The electronic control unit is configured to set a target air-fuel ratio to a rich air-fuel ratio from a time at which fuel cut control for terminating fuel supply to a combustion chamber during operation of the internal combustion engine is terminated to a time at which an output air-fuel ratio of a downstream-side air-fuel ratio sensor becomes a rich determination air-fuel ratio or lower, temporarily set the target air-fuel ratio to the rich air-fuel ratio after the output air-fuel ratio of the downstream-side air-fuel ratio sensor becomes the rich determination air-fuel ratio or lower, and thereafter set the target air-fuel ratio to a lean air-fuel ratio.

The present invention is based on the application of heating resistors by a temperature regulation circuit in certain points of the catalyzer so that this comes into operation in the least time possible, reducing most of the amount of low molecular stability or environmentally harmful substances. Likewise, little tumult are added to each monolith duct to raise exhaust gas turbulence and increase the contact between the reduction and oxidation agent, whether it be platinum, palladium and rhodium.

A method and apparatus for reducing at least one of HC, CO, and NO.sub.x, emissions from an operating internal combustion engine fueled by hydrocarbon or similar fuels, such as alcohols, wherein a portion of the internal combustion chamber has aluminum and/or titanium containing surfaces coated with a titanium dioxide coating further comprising a dopant in and/or on the adherent titanium dioxide coating.

In an engine control method for maintaining performance of oxidation catalyst, fuel of a compressed natural gas engine under a lean-burn condition with an air-fuel equivalence ratio less than or equal to 1 is burned. Activation of the oxidation catalyst for purifying an exhaust gas of the engine is determined. Necessity of a regeneration mode for recovering catalytic activation of the oxidation catalyst according to an activation state of the oxidation catalyst and an operating condition of the engine is determined. And, the air-fuel equivalence ratio is increased to a range of from 1.10 to 1.20 when the oxidation catalyst is inactive and an engine speed is lower than a predetermined speed.