Abstract: A lean NOx trap for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO), and the trapping and reduction of nitrogen oxides (NOx) is disclosed. Nitrogen oxide storage catalysts can comprise a layer on a substrate including ceria-alumina particles having a ceria phase present in a weight percent of the composite in the range of about 20% to about 80% on an oxide basis, an alkaline earth metal component supported on the ceria-alumina particles, wherein the CeO2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size less than 130 ? after aging at 950° C. for 5 hours in 2% O2 and 10% steam in N2.

Abstract: A diesel oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx) is described. More particularly, the present invention is directed to a washcoat composition comprising high silica to alumina zeolite and platinum and palladium such that the zeolite minimizes negative interactions of these platinum group metals with the zeolite.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: Described is a selective catalytic reduction catalyst comprising a zeolitic framework material of silicon and aluminum atoms, wherein a fraction of the silicon atoms are isomorphously substituted with a tetravalent metal. The catalyst can include a promoter metal such that the catalyst effectively promotes the reaction of ammonia with nitrogen oxides to form nitrogen and H2O selectively over a temperature range of 150 to 650° C. In another aspect, described is a selective catalytic reduction composite comprising an SCR catalyst material and an ammonia storage material comprising a transition metal having an oxidation state of IV. The SCR catalyst material promotes the reaction of ammonia with nitrogen oxides to form nitrogen and H2O selectively over a temperature range of 150° C. to 600° C., and the SCR catalyst material is effective to store ammonia at temperatures of 400° C. and above.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: A layered catalyst composite for the treatment of exhaust gas emissions, effective to provide lean NOx trap functionality and three-way conversion functionality is described. Layered catalyst composites can comprise catalytic material on a substrate, the catalytic material comprising at least two layers. The first layer comprising rare earth oxide-high surface area refractory metal oxide particles, an alkaline earth metal supported on the rare earth oxide-high surface area refractory metal oxide particles, and at least one first platinum group metal component supported on the rare earth oxide-high surface area refractory metal oxide particles. The second layer comprising a second platinum group metal component supported on a first oxygen storage component (OSC) and/or a first refractory metal oxide support and, optionally, a third platinum group metal supported on a second refractory metal oxide support or a second oxygen storage component.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: A diesel oxidation catalyst for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO) and the reduction of nitrogen oxides (NOx) is described. More particularly, the present invention is directed to a washcoat composition comprising high silica to alumina zeolite and platinum and palladium such that the zeolite minimizes negative interactions of these platinum group metals with the zeolite.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25: 1 to about 1:1.

Abstract: A catalyst for the treatment of exhaust gas emissions is disclosed. The catalyst can comprise ceria-alumina particles having a ceria phase present in a weight percent of the composite in the range of about 20% to about 80% on an oxide basis, an alkaline earth metal component supported on the ceria-alumina particles, wherein the CeO2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size less than 160 ? after aging at 950° C. for 5 hours in 2% O2 and 10% steam in N2.

Abstract: The present invention relates to a catalyst composition comprising a carrier substrate, a layer (i) coated on said carrier substrate comprising at least one precious group metal, a layer (ii) comprising Rh, and a layer (iii) comprising Pd and/or Pt and being substantially free of Ce, Ba and Rh, wherein the layer (iii) has a lower weight than the layer (i) or the layer (ii). Furthermore, the present invention relates to a method for treating an exhaust gas stream using said catalyst composition.

Abstract: A lean NOx trap for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO), and the trapping and reduction of nitrogen oxides (NOx) is disclosed. Nitrogen oxide storage catalysts can comprise a layer on a substrate including ceria-alumina particles having a ceria phase present in a weight percent of the composite in the range of about 20% to about 80% on an oxide basis, an alkaline earth metal component supported on the ceria-alumina particles, wherein the CeO2 is present in the form of crystallites that are hydrothermally stable and have an average crystallite size less than 130 ? after aging at 950° C. for 5 hours in 2% O2 and 10% steam in N2.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

Abstract: The present invention relates to a catalyst composition comprising a carrier substrate, a layer (i) coated on said carrier substrate comprising at least one precious group metal, a layer (ii) comprising Rh, and a layer (iii) comprising Pd and/or Pt and being substantially free of Ce, Ba and Rh, wherein the layer (iii) has a lower weight than the layer (i) or the layer (ii). Furthermore, the present invention relates to a method for treating an exhaust gas stream using said catalyst composition.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to aluminum ratio from about 0.25:1 to about 1:1.

Abstract: Catalysts, methods, and systems for treating diesel engine exhaust streams are described. In one or more embodiments, the catalyst comprises platinum, a second metal from one of the groups VB, VIB, VIIB, VIIIB, IB, or IIB of the periodic table, a refractory metal oxide, and a zeolite, the oxidation catalyst already being effective to remove ammonia at temperatures less than about 300° C. and exhibiting no significant decrease in ammonia oxidation efficiency upon hydrothermal aging. A method aspect includes first passing a vehicle's engine exhaust stream through a NOx abatement catalyst; and passing the exhaust stream exiting the NOx abatement catalyst and containing ammonia through the ammonia oxidation catalyst. Systems including such catalysts are also provided.

Abstract: Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.