A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

An engine exhaust system includes an exhaust pipe assembly having an engine exhaust system inlet configured to receive engine exhaust and an engine exhaust system outlet. The system includes a first selective catalytic reduction (SCR) catalyst device positioned downstream in exhaust flow from the engine exhaust system inlet. The first SCR catalyst device includes a substrate with a metallic catalyst coated on the substrate. An electric heater is configured to heat the metallic catalyst. A second SCR catalyst device is positioned downstream in engine exhaust flow from the first SCR catalyst device and upstream of the engine exhaust system outlet. The first SCR catalyst device and the exhaust pipe assembly define an empty chamber between the substrate and the second SCR catalyst device. Engine exhaust flows directly from the substrate to the second SCR catalyst device through the empty chamber.

An oxidation catalyst may include hydrocarbon storage material. One implementation relates to a diesel oxidation catalyst that includes a catalyst having a front zone and a rear zone and a gradient of hydrocarbon storage material on the catalyst extending from the front zone to the rear zone. The gradient of hydrocarbon storage material, may comprise a linear gradient, a step gradient, a parabolic gradient, a logarithmic gradient, or other forms thereof.

An oxidation catalyst is described for treating an exhaust gas from a diesel engine, which oxidation catalyst comprises: a substrate; a first washcoat region disposed on the substrate, wherein the first washcoat region comprises a first platinum group metal (PGM) and a first support material; a second washcoat region adjacent to the first washcoat region, wherein the second washcoat region comprises a second platinum group metal (PGM) and a second support material; a third washcoat region disposed on the substrate, wherein the third washcoat region comprises a third platinum group metal (PGM) and a third support material; and wherein either: (i) the third washcoat region is adjacent to the second washcoat region; or (ii) the second washcoat region is disposed or supported on the third washcoat region. Also described are uses and methods involving the oxidation catalyst.

Described is a selective catalytic reduction material comprising a spherical particle including an agglomeration of crystals of a molecular sieve. The catalyst is a crystalline material that is effective to catalyze the selective catalytic reduction of nitrogen oxides in the presence of a reductant at temperatures between 200° C. and 600° C. A method for selectively reducing nitrogen oxides and an exhaust gas treatment system are also described.

A catalyst system for reducing N.sub.2O emissions in the exhaust system of a vehicle is provided and comprises a support in communication with the exhaust gas stream, with the support including an exhaust gas inlet and an exhaust gas outlet. The support has at least one exhaust gas passage therethrough. The support, which may be in the form of a monolithic, multi-cell honeycomb construction, comprises a first catalytic zone and a second catalytic zone positioned downstream from the first zone. The first catalytic zone includes rhodium or a rhodium-enriched catalyst, while the second catalytic zone includes palladium or a palladium-enriched catalyst.

The invention relates to a coating suspension containing at least one platinum group metal on a support material, as well as manganese(II) carbonate, and to a method for coating a catalyst support substrate.

A two-stage mixer may include a guiding element and a mixing element. The guiding element may be configured to be fixedly mounted to an interior of an exhaust conduit. The mixing element may be configured to be fixedly mounted to the interior of the exhaust conduit in a position downstream from the guiding element. The mixing element may include a central disk, a plurality of mounting arms extending radially from the central disk, and a plurality of blades extending radially from the central disk. At least one mounting arm of the plurality of mounting arms may include a fin extending therefrom, and at least one blade of the plurality of blades may include a fin extending therefrom.

A ship flue gas scrubbing apparatus and scrubbing method are provided. The apparatus includes a housing, an upper scrubbing layer at the upper side inside the housing, and a liquid collecting pool in the lower side inside the housing, a flue gas leading-in port between the scrubbing layer and the liquid collecting pool, a scrubbing seawater inlet above the scrubbing layer, and a cooler located at a flue gas passage between the flue gas inlet outside the housing and the scrubbing layer. The method includes leading flue gas, cooling, injecting scrubbing seawater, scrubbing and other steps.

The present invention relates to a catalyst for the removal of carbon monoxide and hydrocarbon from the exhaust gas of lean-operated internal combustion engines on a supporting body, which bears platinum and/or palladium on one or more refractory carrier materials and also contains cerium oxide and which, after reductive treatment at 250° C. and after CO adsorption, is characterized by certain peaks in Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), and also relates to the use thereof for removing carbon monoxide and hydrocarbon from the exhaust gas of lean-operated internal combustion engines.