Abstract: The present disclosure provides a method of forming a selective catalytic reduction (SCR) catalyst, the method including receiving a first iron-promoted zeolite having a first iron content, and treating the iron-promoted zeolite with additional iron in an ion exchange step to form a second iron-promoted zeolite with a second iron content, the second iron content being higher than the first iron content. A selective catalytic reduction (SCR) catalyst composition including an ironpromoted zeolite having at least about 6 weight percent iron, based on total weight of the ironpromoted zeolite, wherein the iron content of the zeolite was added to the zeolite in at least two separate steps is also provided herein.

Abstract: The present disclosure relates to a process for preparing a catalyst for the selective catalytic reduction of nitrogen oxide. The process includes providing a zeolitic material comprising SiO2 and X2O3 in its framework structure, wherein X is a trivalent element; subjecting the zeolitic material to an ion exchange procedure with one or more copper (II) containing compounds; preparing a slurry comprising the Cu ion-exchanged zeolitic material, one or more iron (II) and/or iron (III) containing compounds, and a solvent system; providing a substrate and coating the slurry onto the substrate; and calcining the coated substrate. Furthermore, the present disclosure relates to a catalyst for the selective catalytic reduction of nitrogen oxide, an exhaust gas treatment system for the treatment of exhaust gas exiting from an internal combustion engine, and a method for the selective catalytic reduction of nitrogen oxides.

Abstract: The present disclosure relates to a process for preparing a catalyst for the selective catalytic reduction of nitrogen oxide. The process includes providing a zeolitic material including SiO2 and X2O3 in its framework structure, wherein X is a trivalent element; subjecting the zeolitic material to an ion exchange procedure with one or more iron (II) and/or iron (III) containing compounds; preparing a slurry including the Fe ion-exchanged zeolitic material, one or more copper (II) containing compounds, and a solvent system; providing a substrate and coating the slurry onto the substrate; and calcining the coated substrate. Furthermore, the present disclosure relates to a catalyst for the selective catalytic reduction of nitrogen oxide, an exhaust gas treatment system for the treatment of exhaust gas exiting from an internal combustion engine, and a method for the selective catalytic reduction of nitrogen oxides.

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: The present disclosure provides a method of forming a selective catalytic reduction (SCR) catalyst, the method including receiving a first iron-promoted zeolite having a first iron content, and treating the iron-promoted zeolite with additional iron in an ion exchange step to form a second iron-promoted zeolite with a second iron content, the second iron content being higher than the first iron content. A selective catalytic reduction (SCR) catalyst composition including an ironpromoted zeolite having at least about 6 weight percent iron, based on total weight of the ironpromoted zeolite, wherein the iron content of the zeolite was added to the zeolite in at least two separate steps is also provided herein.

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: The present disclosure provides catalyst compositions for NOx conversion and catalytic articles incorporating such catalyst compositions. Certain catalyst compositions include a zeolite with a silica-to-alumina ratio from 5 to 20 and sufficient Cu exchanged into cation sites of the zeolite such that the zeolite has a Cu/Al ratio of 0.1 to 0.5 and a CuO loading of 1 to 15 wt. %; and a copper trapping component in a concentration in the range of 1 to 20 wt. %, the copper trapping component including a plurality of particles having a particle size of about 0.5 to 20 microns. Certain catalyst compositions include, as the copper trapping component, alumina present as a plurality of alumina particles with a D90 particle size distribution in the range of 0.5 microns to 20 microns.

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: 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.