Abstract:
Provided are emissions treatment systems for an exhaust stream having an ammonia-generating component, such as a NOx storage reduction (NSR) catalyst or a lean NOx trap (LNT) catalyst, and an SCR catalyst disposed downstream of the ammonia-generating catalyst. The SCR catalyst can be a molecular sieve having the CHA crystal structure, for example SSZ-13 or SAPO-34, which can be ion-exchanged with copper. The LNT can be layered, having an undercoat washcoat layer comprising a support material, at least one precious metal, and at least one NOx sorbent selected from the group consisting of alkaline earth elements, rare earth elements, and combinations thereof and a top washcoat layer comprising a support material, at least one precious metal, and ceria in particulate form, the top washcoat layer being substantially free of alkaline earth components. The emissions treatment system is advantageously used for the treatment of exhaust streams from diesel engines and lean burn gasoline engines.
Abstract:
Provided are diesel exhaust components where palladium is segregated from a molecular sieve, specifically a zeolite, in a catalytic material. In the catalytic material, therefore, there are at least two layers: a palladium-containing layer that is substantially free of a molecular sieve and a hydrocarbon trap layer that comprises at least one molecular sieve and is substantially free of palladium. The palladium is provided on a high surface area, porous refractory metal oxide support. The catalytic material can further comprise a platinum component, where a minor amount of the platinum component is in the hydrocarbon trap layer, and a majority amount of the platinum component is in the palladium-containing layer. Systems and methods of using the same are also provided.
Abstract:
Described is a catalyst, preferably for use in selective catalytic reduction (SCR), said catalyst comprising one or more zeolites of the MFI structure type, and one or more zeolites of the CHA structure type, wherein at least part of the one or more zeolites of the MFI structure type contain iron (Fe), and wherein at least part of the one or more zeolites of the CHA structure type contain copper (Cu). An exhaust gas treatment system is described, comprising said catalyst as well as a process for the treatment of a gas stream comprising NOx using said catalyst as well.
Abstract:
Provided are diesel exhaust components where palladium is segregated from a molecular sieve, specifically a zeolite, in a catalytic material. In the catalytic material, therefore, there are at least two layers: a palladium-containing layer that is substantially free of a molecular sieve and a hydrocarbon trap layer that comprises at least one molecular sieve and is substantially free of palladium. The palladium is provided on a high surface area, porous refractory metal oxide support. The catalytic material can further comprise a platinum component, where a minor amount of the platinum component is in the hydrocarbon trap layer, and a majority amount of the platinum component is in the palladium-containing layer. Systems and methods of using the same are also provided.
Abstract:
Provided is a diesel oxidation catalyst for the treatment of exhaust gas emissions from a diesel engine and a method for treating a diesel exhaust gas stream, the method comprising providing a diesel oxidation catalyst and contacting said diesel exhaust gas stream with said diesel oxidation catalyst for the treatment of exhaust gas emissions. More particularly, the present invention is directed to a catalyst structure comprising three distinct layers; in which layer comprises a precious metal component such as palladium is located between two hydrocarbon storage layers comprising a molecular sieve such as a zeolite.
Abstract:
Disclosed is a catalyst, preferably for use in selective catalytic reduction (SCR), said catalyst comprising one or more zeolites of the MFI structure type, and one or more zeolites of the BEA structure type, wherein at least part of the one or more zeolites of the MFI structure type and at least part of the one or more zeolites of the BEA structure type respectively contain iron (Fe). Furthermore, an exhaust gas treatment system is described, comprising said catalyst as well as a process for the treatment of a gas stream comprising NOx using said catalyst as well.
Abstract:
A multilayered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. Provided is a catalytic material of at least four layers in conjunction with a carrier, where each of the layers includes a support, at least three layers comprise a precious metal component, and at least one layer comprises an oxygen storage component (OSC). The catalytic material can further comprise a fifth layer, where at least four layers comprise a precious metal component, at least one layer comprises an oxygen storage component, and at least one layer is substantially free of an oxygen storage component.
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:
The present invention relates to a treatment system for a gasoline engine exhaust gas stream comprising a particulate filter, said particulate filter comprising: a particulate filter substrate, an inlet layer disposed on the exhaust gas inlet surface of the filter substrate, and an outlet layer disposed on the exhaust gas outlet surface of the filter substrate, wherein the inlet layer comprises Rh and/or Pd, and the outlet layer comprises Rh and/or a zeolite.
Abstract:
Disclosed is a catalyzed soot filter with layered design wherein the first coating of the filter comprises an oxidation catalyst comprising platinum (Pt) and optionally palladium (Pd), wherein the second coating of the filter comprises an oxidation catalyst comprising Pd and optionally Pt, wherein the Pt concentration in the second coating is lower than the Pt concentration in the first coating, and wherein the weight ratio of Pt:Pd in the second coating is in the range of from 1:1 to 0:1; and wherein the first coating and the second coating are present on the wall flow substrate at a coating loading ratio in the range of from 0.25 to 3, calculated as ratio of the loading of the first coating (in g/inch3 (g/(2.54 cm)3)): loading of the second coating (in g/inch3 (g/(2.54 cm)3)).
Abstract translation:公开了一种具有分层设计的催化烟灰过滤器,其中过滤器的第一涂层包括包含铂(Pt)和任选的钯(Pd)的氧化催化剂,其中过滤器的第二涂层包含包含Pd和任选的Pt的氧化催化剂,其中 第二涂层中的Pt浓度低于第一涂层中的Pt浓度,其中第二涂层中Pt:Pd的重量比在1:1至0:1的范围内; 并且其中所述第一涂层和所述第二涂层以基于所述第一涂层的负载比(以g / inch 3(g /(3 / g)(2.54)计)的0.25至3的涂层负载比率存在于所述壁流动基材上 cm)3)):第二涂层的负载(g / inch 3(g /(2.54cm)3)))。