An internal combustion engine system includes a combustor arranged to repetitively receive air and fuel, combust the received air and fuel, and expand the combusted air and fuel, an expander including a cylinder and a piston arranged to reciprocate in the cylinder, the piston being connected to a crankshaft of the engine system, and an exhaust guide arranged to guide exhaust gases from the combustor to the expander, wherein the system is arranged to provide an injection of fuel into the exhaust guide and/or arranged to provide an injection of fuel into the combustor after a combustion in the combustor and before a reception of air and fuel in the combustor for a subsequent combustion.

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.

An exhaust purification system of an internal combustion engine provided with a heat and hydrogen generation device (50) and an exhaust purification catalyst (14) comprised of the three way catalyst. Heat and hydrogen generated in the heat and hydrogen generation device (50) is fed to the exhaust purification catalyst (14). When an air-fuel ratio of the air and fuel made to burn in the heat and hydrogen generation device (50) is made a predetermined target set air-fuel ratio, the air-fuel ratio of the exhaust gas discharged from the engine is controlled to the target adjusted air-fuel ratio required for making the air-fuel ratio of the gas flowing into the exhaust purification catalyst (14) the stoichiometric air-fuel ratio.

Provided are compositions, articles, systems and methods that comprise or use a catalyst composition comprising a zeolite having an LTA structure with iron, manganese or a combination thereof as an extra-framework metal. The zeolite can have a mole ratio of silica-to-alumina (SAR) of about 15 to about 70 and can contain about 0.5 to about 10 weight percent, based on the total weight of the zeolite, of extra-framework iron, manganese or a combination thereof.

An integrated vehicle on-board system configured to generate hydrogen and to introduce the generated hydrogen into an exhaust gas stream of an internal combustion engine, the system including a water-splitting article configured to split water into hydrogen and oxygen and a hydrogen injection article configured to introduce the hydrogen into the exhaust gas stream, is effective for the abatement of carbon monoxide and/or hydrocarbons and/or nitrogen oxides. The introduction of hydrogen may be intermittent and/or during a cold-start period.

The invention relates to a catalyst device for purifying exhaust gases containing nitrogen oxide by using selective catalytic reduction (SCR), the catalyst device comprising at least two catalytic layers, the first layer containing vanadium oxide and a mixed oxide comprising titanium oxide and silicon oxide and the second layer containing a molecular sieve containing iron, wherein the first layer is applied onto the second layer. The invention also relates to uses of the catalyst device and a method for purifying exhaust gases.

Certain catalytic articles, systems or methods provide for excellent NOx conversion and are especially suitable for low temperature NOx conversion. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles or systems contain an upstream SCR composition and a downstream LNT composition. The substrate(s) may advantageously be electrically heated.

A microporous crystalline material having a molar silica to alumina ratio (SAR) ranging from 10 to 15 and a fraction of Al in the zeolite framework of 0.63 or greater is disclosed. A method of selective catalytic reduction of nitrogen oxides in exhaust gas that comprises contacting exhaust gases, typically in the presence of ammonia, urea, an ammonia generating compound, or a hydrocarbon compound, with an article comprising the disclosed microporous crystalline is also disclosed. Further, a method of making the disclosed microporous crystalline material is disclosed.

An NH.sub.3 supply amount controller reduces and adjusts a supply amount of NH.sub.3 to an SCR catalyst by an NH.sub.3 supplier, when an exhaust gas flowing into an NO.sub.X catalyst has a rich air-fuel ratio and NO.sub.X occluded by the NO.sub.X catalyst is reduced to N.sub.2. A reduction amount of the supply amount of the NH.sub.3 controlled by the NH.sub.3 supply amount controller is set smaller when a temperature of the NO.sub.X catalyst detected or estimated by an NO.sub.X catalyst temperature detector is higher.

An internal combustion engine, exhaust system, exhaust gas treatment device includes an housing (18) including a housing inlet (34) and a housing outlet (60). An exhaust gas treatment unit (28), in the housing, includes an inlet (32) following the housing inlet and an outlet (38). An SCR catalytic converter device (30), in the housing, includes an SCR catalytic converter device inlet (54) following the exhaust gas treatment unit outlet and an SCR catalytic converter device outlet (56). A reactant releasing device (52) releases reactant upstream of the SCR catalytic converter device inlet. An exhaust gas duct (42), formed in an exhaust gas pipe (44), leads in the housing from the exhaust gas treatment unit outlet to the SCR catalytic converter device inlet, whereby exhaust gas leaving the SCR catalytic converter device at the SCR catalytic converter device outlet flows around the exhaust gas pipe in at least some areas.