Abstract: The present invention relates to a catalyst for the selective catalytic reduction of nitrogen oxide, the catalyst comprising a first coating comprising a 12-membered ring pore zeolitic material comprising a first metal which is one or more of copper and iron, and a second coating comprising an 8-membered ring pore zeolitic material comprising a second metal which is one or more of copper and iron.

Abstract: The present invention relates to a process for preparing a catalyst for the selective catalytic reduction of nitrogen oxide comprising, among other steps, preparing a second aqueous mixture comprising water and an iron salt; and disposing the second mixture on the substrate obtained according to (ii), comprising a coating comprising a zeolitic material comprising copper, over y % of the substrate axial length from the inlet end to the outlet end of the substrate, wherein y is in the range of from 10 to x, obtaining a substrate comprising, in a first zone, the coating comprising a zeolitic material comprising copper and over y % of the substrate axial length an iron salt; and, if x > y, in a second zone extending from y % to x % of the substrate axial length from the inlet end to the outlet end, the coating comprising a zeolitic material comprising copper.

Abstract: Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings containing copper-containing molecular sieves disposed thereon, where for example a concentration of catalytic copper in an upstream zone is lower than the concentration of catalytic copper in a downstream zone.

Abstract: Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

Abstract: Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings disposed thereon, for example, a zoned coating comprising an upstream zone comprising a coating layer comprising a steam-activated iron-containing molecular sieve and a downstream zone comprising a coating layer comprising a high copper-containing molecular sieve.

Abstract: Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

Abstract: A system for treatment of an exhaust gas stream from an engine is provided, containing an upstream selective catalytic reduction (SCR) catalyst, which receives the exhaust gas stream without any intervening catalyst, a diesel oxidation catalyst (DOC) positioned downstream thereof; a catalyzed soot filter (CSF) downstream of the diesel oxidation catalyst; a second SCR catalyst positioned downstream of the catalyzed soot filter; and an ammonia oxidation (AMOx) catalyst. The application also describes use of such systems to reduce nitrogen oxides (NOx) and hydrocarbons (HC) in an exhaust gas stream.

Abstract: The present invention relates to a catalytic article comprising a substrate having a catalyst composition disposed thereon, wherein the catalyst composition comprises a platinum group metal impregnated onto a porous support and a selective catalytic reduction catalyst, wherein the catalyst composition is substantially free of platinum; and wherein the catalytic article is effective in the abatement of nitrogen oxides (NOx) and hydrocarbons (HCs). The present invention further relates to exhaust gas treatment systems for treating an exhaust gas stream exiting a diesel engine.

Abstract: 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.

Abstract: A system for treatment of an exhaust gas stream from an engine is provided, containing an upstream selective catalytic reduction (SCR) catalyst, which receives the exhaust gas stream without any intervening catalyst, a diesel oxidation catalyst (DOC) positioned downstream thereof; a catalyzed soot filter (CSF) downstream of the diesel oxidation catalyst; a second SCR catalyst positioned downstream of the catalyzed soot filter; and an ammonia oxidation (AMOx) catalyst. The application also describes use of such systems to reduce nitrogen oxides (NOx) and hydrocarbons (HC) in an exhaust gas stream.

Abstract: The present invention relates to a catalytic article comprising a substrate having a catalyst composition disposed thereon, wherein the catalyst composition comprises a platinum group metal impregnated onto a porous support and a selective catalytic reduction catalyst, wherein the catalyst composition is substantially free of platinum; and wherein the catalytic article is effective in the abatement of nitrogen oxides (NOx) and hydrocarbons (HCs). The present invention further relates to exhaust gas treatment systems for treating an exhaust gas stream exiting a diesel engine.

Abstract: Described are compositions and catalytic articles comprising both a first molecular sieve promoted with copper and a second molecular sieve promoted with iron, the first and second molecular sieves having a d6r unit and the first molecular sieves having cubic shaped crystals with an average crystal size of about 0.5 to about 2 microns. The weight ratio of the copper-promoted molecular sieve to the iron-promoted molecular sieve can be about 1:1 to about 4:1. The catalytic articles are useful in methods and systems to catalyze the reduction of nitrogen oxides in the presence of a reductant.

Abstract: Described is a catalyst composition suitable for use as a selective catalytic reduction catalyst, including small-pore molecular sieve particles having a pore structure and a maximum ring size of eight tetrahedral atoms and impregnated with a promoter metal, and metal oxide particles dispersed within the small-pore molecular sieve particles and external to the pore structure of the small-pore molecular sieve particles, wherein the metal oxide particles include one or more oxides of a transition metal or lanthanide of Group 3 or Group 4 of the Periodic Table. A method for preparing the catalyst, a method for selectively reducing nitrogen oxides, and an exhaust gas treatment system are also described.

Abstract: Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings disposed thereon, for example, a zoned coating comprising an upstream zone comprising a coating layer comprising a steam-activated iron-containing molecular sieve and a downstream zone comprising a coating layer comprising a high copper-containing molecular sieve.

Abstract: Certain selective catalytic reduction (SCR) articles, systems and methods provide for high NOx conversion while at the same time low N2O formation. The articles, systems and methods are suitable for instance for the treatment of exhaust gas of diesel engines. Certain articles have zoned coatings containing copper-containing molecular sieves disposed thereon, where for example a concentration of catalytic copper in an upstream zone is lower than the concentration of catalytic copper in a downstream zone.

Abstract: Described is a catalyst composition suitable for use as a selective catalytic reduction catalyst, including small-pore molecular sieve particles having a pore structure and a maximum ring size of eight tetrahedral atoms and impregnated with a promoter metal, and metal oxide particles dispersed within the small-pore molecular sieve particles and external to the pore structure of the small-pore molecular sieve particles, wherein the metal oxide particles include one or more oxides of a transition metal or lanthanide of Group 3 or Group 4 of the Periodic Table. A method for preparing the catalyst, a method for selectively reducing nitrogen oxides, and an exhaust gas treatment system are also described.

Abstract: Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

Abstract: Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

Abstract: 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.

Abstract: Provided are catalyst articles, methods and systems for treating lean burn engine exhaust. Catalyst articles include selective catalytic reduction catalyst on a particulate filter. The SCR catalyst on the particulate filter provides limited NOx conversion so that unconverted NO2 is available to facilitate passive oxidation of soot trapped on the particulate filter by reaction with NO2. Systems and methods utilize such catalytic articles, and further include, e.g., a downstream selective catalytic reduction catalyst on a flow through substrate.