摘要:
The present invention relates to a layered diesel oxidation catalyst (DOC) comprising: a) a carrier substrate; b) a diesel oxidation catalytic material comprising b1) a first layer located on the carrier substrate, the first layer comprising palladium impregnated on a support material comprising ceria in an amount of at least 45 weight-% based on the total weight of the support material, and optionally comprising platinum; b2) a second layer located on the first layer, the second layer comprising palladium and platinum each impregnated on a support material comprising a metal oxide; wherein the platinum to palladium weight ratio of the first layer is lower than the platinum to palladium weight ratio of the second layer.
摘要:
An emission control catalyst includes copper-ceria to boost low temperature CO oxidation performance, generate exothermic heat during the process, and reduce HC and NOx emissions. As a result, system performance is boosted at equal catalyst cost or maintained at a reduced catalyst cost. In one embodiment, an engine exhaust catalyst includes a first washcoat layer having at least one of a platinum-based catalyst, a palladium-based catalyst, and combinations thereof; and a second washcoat layer having copper-ceria.
摘要:
A diesel engine exhaust treatment system and method is provided which utilizes a diesel particulate filter positioned in the exhaust gas stream of a vehicle which includes an SCR catalyst, an ammonia oxidation catalyst, and/or a diesel oxidation catalyst. The system is capable of performing multiple functions including converting NOx to N2, converting HC and CO to H2O and CO2, trapping particulates, and minimizing ammonia emissions. The system is more compact and efficient than prior systems utilizing separate catalyst units, and minimizes backpressure while maximizing catalyst performance.
摘要:
An exhaust gas oxidation catalyst characterized as an exhaust gas oxidation catalyst comprising a catalyst substrate, wherein a plurality of exhaust gas channels has been formed, and a catalyst layer formed on the surface of the exhaust gas channels in the catalyst substrate; wherein a catalyst layer consisting of a bottom catalyst layer, a top catalyst layer exposed within the exhaust gas channels, and an intermediate catalyst layer located between the bottom catalyst layer and top catalyst layer, is provided so as to cover not less than 25% of the exhaust gas channel surface, and wherein the bottom catalyst layer contains at least an oxygen-occluding agent as catalyst component but does not contain a hydrocarbon adsorbent, the intermediate catalyst layer contains at least catalyst metal, supported on a metal oxide support, and a hydrocarbon adsorbent as catalyst components, and the top catalyst layer contains at least an oxygen-occluding agent and a hydrocarbon adsorbent as catalyst components.
摘要:
Inside an engine exhaust passage, in order from the upstream side, a hydrocarbon feed valve, oxidation catalyst, and exhaust purification catalyst are arranged. A first NOx purification method which lowers the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst by a predetermined period while maintaining it lean so as to remove NOx without causing NOx to be stored in the form of nitrates and a second NOx purification method which switches the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst from lean to rich by a period longer than the above period so as to remove NOx are selectively used in accordance with an operating state of the engine.
摘要:
An exhaust gas purification device is provided. The device includes: in an exhaust gas passage for a combustion exhaust gas containing a nitrogen oxide, a hydrocarbon, and an oxygen in a larger amount than a theoretical reaction amount with respect to the hydrocarbon to flow therethrough, in order from upstream, a first catalyst part for selectively reducing a nitrogen oxide; a plasma discharge part for generating a plasma; a second catalyst part for selectively reducing a nitrogen oxide; and a purifying catalyst part for purifying a reducing agent.
摘要:
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.
摘要:
An emission control catalyst that exhibits improved CO and HC reduction performance includes supported precious group metal catalysts that are coated onto different layers of the substrate for the emission control catalyst. Zeolites of one or more types are added to the emission control catalyst as a hydrocarbon absorbing component to boost the low temperature performance of the emission control catalyst. Y zeolite is used by itself or mixed with other zeolites to enhance hydrocarbon storage at low temperatures.
摘要:
The present invention disclosed a tri-layer structured metal composite oxides material which used in a catalyst coat for purifying vehicle exhaust gas, and the method for manufacturing the same.
摘要:
Described is a catalyst comprising a substrate and a catalyst coating of two or more layers: (a) a first layer comprising Pd and Rh on the substrate; and (b) a second layer comprising Pt and/or Pd on the first layer; these layers each further comprising: one or more particulate support materials; one or more oxygen storage component (OSC) materials; and one or more nitrogen oxide storage materials comprising one or more elements selected from the group of alkali and/or alkaline earth metals, wherein the total amount of alkali and alkaline earth metals ranges from 0.18 to 2.0 g/in3 calculated as the respective alkali metal oxides M2O and alkaline earth metal oxides MO. Also described is a method for the production of a catalyst, as well as a process for the treatment of a gas stream, in particular of an exhaust gas stream resulting from an internal combustion engine.
摘要翻译:描述了一种催化剂,其包括基材和两层或更多层的催化剂涂层:(a)在基材上包含Pd和Rh的第一层; 和(b)在第一层上包含Pt和/或Pd的第二层; 这些层还包括:一种或多种颗粒状载体材料; 一种或多种储氧组分(OSC); 和一种或多种氮氧化物储存材料,其包含选自碱金属和/或碱土金属的一种或多种元素,其中碱金属和碱土金属的总量为0.18至2.0g / in 3,其计算为各自的碱金属 氧化物M2O和碱土金属氧化物MO。 还描述了一种用于生产催化剂的方法,以及用于处理气流,特别是由内燃机产生的废气流的方法。