An exhaust gas aftertreatment system for an internal combustion engine includes an inlet conduit, a reductant decomposition chamber, a first selective catalytic reduction (SCR) catalyst member, a second SCR catalyst member, a mixing chamber, a particulate filter, a reductant delivery system, and a hydrocarbon delivery system. The inlet conduit is configured to receive exhaust gas from the internal combustion engine. The reductant decomposition chamber is fluidly coupled to the inlet conduit and configured to receive the exhaust gas from the inlet conduit. The first SCR catalyst member is fluidly coupled to the reductant decomposition chamber and configured to receive the exhaust gas from the reductant decomposition chamber. The second SCR catalyst member is fluidly coupled to the first SCR catalyst member and is configured to receive the exhaust gas from the first SCR catalyst member.

A vehicle system includes a diesel oxidation catalyst. The vehicle system includes a hydrocarbon-selective catalytic reduction unit located downstream of the diesel oxidation catalyst. The hydrocarbon-selective catalytic reduction unit is configured to receive exhaust gas from the diesel oxidation catalyst. The vehicle system includes a turbocharger located downstream of the hydrocarbon-selective catalytic reduction unit. The turbocharger is configured to receive exhaust gas from the hydrocarbon-selective catalytic reduction unit.

A catalyst for oxidising ammonia comprises a selective catalytic reduction (SCR) catalyst and a composite heterogeneous extruded honeycomb having longitudinally extending parallel channels, which channels being defined in part by channel walls having a total longitudinal length, wherein the channel walls comprise a pore structure including a periodic arrangement of porous cells embedded in an inorganic matrix component, at least some of which porous cells are defined at least in part by an active interface layer of a catalytically active material comprising a precious metal supported on particles of a support material.

A exhaust gas mixing apparatus includes an outer cylinder being configured to an insulating ceramic; fins being configured to an insulating ceramic, the fins being provided on an inner side of the outer cylinder; and an electric heating portion embedded in at least a part of the outer cylinder and/or the fins.

Described are exhaust gas treatment systems for treatment of an engine exhaust gas stream containing NOx. The exhaust gas treatment system comprises an engine, a catalyst system including a selective catalytic reduction article comprising two zones, an upstream zone comprising iron-promoted first molecular sieves and a downstream zone comprising copper-promoted second molecular sieves. The catalyst system is effective to reduce high NOx levels in the exhaust gas stream. Also described are methods for treatment of engine exhaust gas streams, comprising treating engine exhaust gas streams containing high NOx levels with catalyst systems including selective catalytic reduction articles having two zones.

Provided are multi-zone catalyst articles, methods of manufacturing multi-zone catalyst articles, and methods for controlling emissions in diesel engine exhaust streams with multi-zone catalyst articles, where the emission treatment system of various embodiments effectively treats diesel engine exhaust with a single multi-zone catalyst article.

The invention relates to a leakage treatment member (50) and an exhaust aftertreatment unit (40) configured to be sealingly arranged in a fluid passage (30) of an exhaust aftertreatment system for treating exhaust from an internal combustion engine, said exhaust aftertreatment unit (40) comprising an exhaust aftertreatment element (42) confined by an outer wall (44) of said exhaust aftertreatment unit, said leakage treatment member being configured to be arranged between:—an inner perimeter (32) of the fluid passage of the exhaust aftertreatment system, and—the outer wall of the exhaust aftertreatment unit, the leakage treatment member comprising an exhaust aftertreatment component for aftertreatment of any leakage of exhaust gases past said aftertreatment unit in said fluid passage.

An after treatment system is disclosed. The after treatment system may include a three-way catalyst (TWC), a selective catalytic reduction (SCR) catalyst, and a CO clean-up catalyst (CUC) on an exhaust pipe through which an exhaust gas flows. The CUC may include a zeolite in which Cu and Fe are ion-exchanged and CeO.sub.2 in which Pt is supported, wherein a weight ratio of the CeO.sub.2 to a total weight of the CUC is 30-70 wt % such that the CUC purifies NH.sub.3 at a lean air/fuel ratio and purifies NH.sub.3 during a delay time at a rich air/fuel ratio.

The invention relates to a catalytic article comprising a substrate having an inlet and an outlet; a first coating comprising a blend of: (1) platinum on a support, and (2) a first SCR catalyst comprising a Cu- and Mn-exchanged molecular sieve; and a second coating comprising a second SCR catalyst; wherein the support comprises at least one of a zeolite or a SiO.sub.2-Al.sub.2O.sub.3 mixed oxide. The platinum may be fixed on the support in solution.

An engine system includes a hydrogen combustion engine and an exhaust aftertreatment system, EATS, configured to reduce emissions of the engine exhausts. The EATS comprises: an exhaust gas inlet for receiving engine exhaust from the hydrogen combustion engine; a plurality of emission reducing modules arranged downstream of the exhaust gas inlet and being configured to reduce emissions of the engine exhausts, the plurality of emission reducing modules comprising at least a first emission reducing module with a porous substrate including a powder coating and a selective catalyst reduction, SCR, coating, and a second emission reducing module being a selective catalyst reduction, SCR, catalyst unit. At least one of the first and second emission reducing modules is arranged as the first occurring emission reducing module of the EATS downstream of the exhaust gas inlet.