摘要:
A process for treating exhaust gas from a compression ignition engine wherein substantially all fuel for combustion is injected into a combustion chamber prior to the start of combustion comprises contacting the exhaust gas with a catalyst comprising a supported palladium (Pd) catalyst.
摘要:
A method of making a supported catalytic species comprising an alloy of at least two metals, comprises the steps of: (i) combining a particulate support material, a solution of a first metal compound, a solution of a second metal compound, and a solution of an alkaline precipitating agent to form a slurry mixture; (ii) agitating the resultant mixture; and (iii) contacting the solids with a reducing agent, wherein the first metal in the first metal compound and the second metal in the second metal compound is each independently selected from the group consisting of gold, palladium, platinum, rhodium, iridium, silver, osmium and ruthenium; and wherein the first metal is not the same as the second metal.
摘要:
An exhaust system for an internal combustion engine, which system comprises a monolith substrate (10) coated with a catalyst, which monolith substrate comprising a plurality of substantially parallel channels, each channel having a length extending from an upstream end to a downstream end; and a first sensor disposed in a hole (16) defined in part by an external wall of the monolith substrate, wherein the monolith substrate comprises a portion (12) of the plurality of channels wherein the catalyst composition in at least a part of the length of channels extending from the upstream end has an increased activity for a reaction for which the catalyst composition is intended relative to catalyst composition in a remainder (14) of the monolith substrate, the arrangement being such that the sensor is contacted substantially only with exhaust gas that has first contacted the catalyst composition having an increased activity.
摘要:
A vehicle comprises a compression ignition engine provided with engine management means and having a catalyst for exhaust gas aftertreatment, wherein the engine management means is configured, when in use, to detect idle conditions and upon determining that idle conditions exist, stops the engine entirely, wherein the catalyst comprises a honeycomb substrate monolith coated with a catalytic washcoat comprising one or more precious metal, which catalytic washcoat being arranged between a first, upstream washcoat zone and a second, downstream washcoat zone, wherein a thermal mass in the first washcoat zone is different from a thermal mass in the second washcoat zone and wherein a washcoat layer in the first, upstream washcoat zone is substantially contiguous with a washcoat layer in the second, downstream washcoat zone.
摘要:
An exhaust system, and a catalyzed substrate for use in an exhaust system, is disclosed. The exhaust system comprises a lean NOx trap and the catalyzed substrate. The catalyzed substrate has a first zone, having a platinum group metal loaded on a support, and a second zone, having copper or iron loaded on a zeolite. The first zone or second zone additionally comprises a base metal oxide or a base metal loaded on an inorganic oxide. Also provided are methods for treating an exhaust gas from an internal combustion engine using the exhaust system. The exhaust system is capable of storing NH3 generated in rich purging, reacting the NH3 with slip NOx, controlling H2S released from NOx trap desulfation, and oxidizing slip hydrocarbons and carbon monoxide. When the catalyzed substrate is a filter substrate, it is also capable of removing soot from exhaust system.
摘要:
An exhaust system for a lean-burn internal combustion engine comprises a catalyst for oxidising carbon monoxide and hydrocarbons comprising a flow-through substrate monolith comprising a first platinum group metal (PGM) zone containing at least one PGM supported on a surface area-increasing washcoat component, a second PGM zone containing at least one PGM supported on a surface area-increasing washcoat component, a third PGM zone containing at least one PGM supported on a surface area-increasing washcoat component wherein both the PGM loading in the first PGM zone and the PGM loading in the third PGM zone is greater than the PGM loading in the second PGM zone and wherein the first PGM zone comprises a washcoat loading that is less than a washcoat loading of the third PGM zone.
摘要:
A system for treating a gas stream containing nitrogen oxides (NOx) and particulates flowing in the system comprises means for injecting a source of ammonia (NH3) or urea (CO(NH2)2) into a flowing exhaust gas upstream of a precious metal-free particulate trap, a selective catalytic reduction catalyst disposed downstream of the particulate trap and a source of ammonia or urea.
摘要:
An exhaust system for a lean-burn internal combustion engine comprises a catalyst for oxidising carbon monoxide and hydrocarbons comprising a flow-through substrate monolith comprising a first platinum group metal (PGM) zone containing at least one PGM supported on a surface area-increasing washcoat component, a second PGM zone containing at least one PGM supported on a surface area-increasing washcoat component, a third PGM zone containing at least one PGM supported on a surface area-increasing washcoat component wherein both the PGM loading in the first PGM zone and the PGM loading in the third PGM zone is greater than the PGM loading in the second PGM zone and wherein the first PGM zone comprises a washcoat loading that is less than a washcoat loading of the third PGM zone.
摘要:
An improved system for treating the aftertreatment of exhaust gases, especially from diesel engines, comprises a first catalyst (20) effective to oxidise hydrocarbons, a second catalyst (22) effective to convert NO to NO2, a trap (24) for particulates, on which particulates may combust with the NO2, and optionally a NOx absorption material (26).
摘要:
A method of making a supported catalytic species comprising an alloy of at least two metals, comprises the steps of: (i) combining a particulate support material, a solution of a first metal compound, a solution of a second metal compound, and a solution of an alkaline precipitating agent to form a slurry mixture; (ii) agitating the resultant mixture; and (iii) contacting the solids with a reducing agent, wherein the first metal in the first metal compound and the second metal in the second metal compound is each independently selected from the group consisting of gold, palladium, platinum, rhodium, iridium, silver, osmium and ruthenium; and wherein the first metal is not the same as the second metal.