Abstract: An apparatus comprising a compression ignition engine and an exhaust system therefor comprising at least one exhaust system component for treating exhaust gas and means for generating an exotherm for heating the at least one exhaust system component, which exotherm generating means consisting essentially of a catalyst and means for injecting hydrocarbon into exhaust gas for combustion on the catalyst, which catalyst consisting essentially of both a palladium (Pd) component and a platinum (Pt) component, and an optional support material, disposed on a substrate monolith.

Abstract: An apparatus comprises: (i) a lean burn internal combustion engine; (ii) an exhaust system for treating a flowing exhaust gas from the engine, which system comprising: (a) a first substrate monolith comprising a NOx adsorber catalyst (NAC); and (b) a catalysed soot filter (CSF) comprising a filter substrate; and (iii) means for enriching the exhaust gas to provide an enriched exhaust gas composition intermittently during normal lean running operation for removing sulfate adsorbed on the NAC, wherein the exhaust system comprises: (c) a compound located downstream of at least some of the NAC, which compound is effective to remove and/or convert at least some hydrogen sulfide in enriched exhaust gas derived from removing sulfate adsorbed on the NAC.

Abstract: An apparatus comprising a compression ignition engine and an exhaust system therefor comprising at least one exhaust system component for treating exhaust gas and means for generating an exotherm for heating the at least one exhaust system component, which exotherm generating means consisting essentially of a catalyst and means for injecting hydrocarbon into exhaust gas for combustion on the catalyst, which catalyst consisting essentially of both a palladium (Pd) component and a platinum (Pt) component, and an optional support material, disposed on a substrate monolith.

Abstract: A method of decomposing nitrogen dioxide to nitrogen monoxide in an exhaust gas of a lean-burn internal combustion engine, such as a diesel engine, comprises adjusting the C1 hydrocarbon:nitrogen oxides (C1 HC:NOx) ratio of the exhaust gas to from 0.1 to 2 and contacting this exhaust gas mixture with a particulate acidic refractory oxide selected from the group consisting of zeolites, tungsten-doped titania, silica-titania, zirconia-titania, gamma-alumina, amorphous silica-alumina and mixtures of any two or more thereof and passing the effluent gas to atmosphere.

Abstract: An exhaust system for a vehicular lean-burn internal combustion engine includes a NOx reduction catalyst, a source reductant, means (20) for contacting the catalyst with the reductant, means for sensing the temperature of the exhaust gas and/or the catalyst bed and means, when in use, for controlling reductant addition. The reductant addition control means supplies an amount of reductant to the catalyst at a rate corresponding to a measured temperature value of the exhaust gas and/or catalyst bed, which temperature value has been pre-determined to correlate, in use, with an amount of NOx in the exhaust gas.

Abstract: A method of reducing nitrogen oxides (NOx) in a flowing combustion exhaust gas to N2, which method comprising oxidising nitrogen monoxide to nitrogen dioxide on a transition metal/elite catalyst at catalyst bed temperatures below 50° C. and reducing NOx with the catalyst using an hydrocarbon (HC) reductant at catalyst bed temperatures below 150° C.

Abstract: An apparatus comprising a compression ignition engine and an exhaust system therefor comprising at least one exhaust system component for treating exhaust gas and means for generating an exotherm for heating the at least one exhaust system component, which exotherm generating means consisting essentially of a catalyst and means for injecting hydrocarbon into exhaust gas for combustion on the catalyst, which catalyst consisting essentially of both a palladium (Pd) component and a platinum (Pt) component, and an optional support material, disposed on a substrate monolith.

Abstract: A method of selectively catalysing the reduction of NOx in an exhaust gas flowing in an exhaust system of an internal combustion engine comprising a filter (40) for particulate matter comprising a catalyst capable of selectively catalysing the reduction of NOx with a reducing agent, which method comprising introducing a reducing agent, or a precursor thereof, into the exhaust gas and contacting the resulting gas with the filter (40).

Abstract: A catalyst system includes a three-way catalyst (TWC) mounted underfloor and an engine management system programmed to initiate an enrichment of the exhaust gases exiting the engine with at least one of CO and hydrocarbons and to add secondary air to the exhaust gases in the exhaust passage upstream of the TWC. This periodic enrichment and addition of secondary air causes catalytic oxidation of the at least one of CO and hydrocarbons over the TWC thereby raising the underfloor TWC temperature to at least 550° C., preferably higher, in order to reduce sulphur poisoning of the catalyst and maintain the desired catalytic activity.

Abstract: A system for converting particulate matter in exhaust gases, which system comprises a stoichiometrically-operated engine and an exhaust system including a plasma generator for converting water vapor in the exhaust gases into an oxidant and a filter downstream of the plasma generator. A method for converting particulate matter (PM) in exhaust gases by using plasma-treated water vapor as an oxidant to convert PM trapped on a filter disposed in an exhaust system, and/or to oxidize NO and/or N2 to NO2, in which water vapor, PM, NO and N2 are present in the exhaust gases of a stoichiometrically-operated gasoline engine. The NO2 is then used to combust the PM. Experimentally, the conversion of a gaseous hydrocarbon using a plasma with and without water vapor present can be followed using mass spectrometry.