Abstract:
Provided is a catalyst composition, in particular a diesel oxidation catalyst, for the treatment of exhaust gas emissions, such as the oxidation of unburned hydrocarbons (HC), and carbon monoxide (CO). More particularly, the present invention is directed to a catalyst structure comprising at least two, specifically three distinct layers, at least one of which contains an oxygen storage component (OSC) that is present in a layer separate from the majority of the platinum group metal (PGM) components, such as palladium and platinum.
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 NO x abatement catalyst; and passing the exhaust stream exiting the NO x abatement catalyst and containing ammonia through the ammonia oxidation catalyst. Systems including such catalysts are also provided.
Abstract translation:描述了用于处理柴油机废气流的催化剂,方法和系统。 在一个或多个实施方案中,催化剂包含铂,来自元素周期表中VB,VIB,VIIB,VIIIB,IB或IIB族的第二种金属,难熔金属氧化物和沸石,氧化催化剂已经是 在低于约300℃的温度下有效去除氨,并且在水热老化时氨氧化效率没有显着降低。 方法方面包括首先使车辆的发动机废气流通过NO x减少催化剂; 并使离开NO x x减少催化剂的废气流通过氨氧化催化剂。 还提供了包括这种催化剂的体系。
Abstract:
Nitrogen oxide storage materials and methods of manufacturing nitrogen oxide storage materials are disclosed. The nitrogen oxide storage materials can be used to manufacture catalytic trap disposed in an exhaust passage of an internal combustion engine which is operated periodically between lean and stoichiometric or rich conditions, for abatement of NOx in an exhaust gas stream which is generated by the engine. In one embodiment, the nitrogen oxide storage material comprises alkaline earth material supported on ceria particles having a crystallite size of between about 10 and 20 nm and the alkaline earth oxide having a crystallite size of between about 20-40 nm.