摘要:
Disclosed are processes for the preparation of copper containing molecular sieves with the CHA structure having a silica to alumina mole ratio greater than about 10, wherein the copper exchange step is conducted via wet state exchanged and prior to the coating step and wherein in the copper exchange step a liquid copper solution is used wherein the concentration of copper is in the range of about 0.001 to about 0.25 molar using copper acetate and/or an ammoniacal solution of copper ions as copper source. Catalysts made by the processes, catalyst systems and methods of treating exhaust gas with the molecular sieves and catalysts are also disclosed.
摘要:
Catalysts comprising metal-loaded non-zeolitic molecular sieves having the CHA crystal structure, including Cu-SAPO-34, methods for preparing such catalysts, and systems and methods for treating exhaust gas incorporating such catalysts are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stability at high reaction temperatures.
摘要:
Catalysts, catalyst systems, and methods for removing ammonia and/or carbon monoxide in flue gases are provided where ammonia is used with a selective catalytic reduction catalyst for reducing oxides of nitrogen. A dual oxidation catalyst generally comprises an alkali component, a transition metal, and a metal oxide support. This catalyst is also substantially free from precious metal components and effective for substantially simultaneously oxidizing ammonia (NH 3 ) and carbon monoxide (CO) when placed in an exhaust gas stream. The catalyst is effective to provide low ammonia to nitrogen oxides selectivity.
摘要:
Catalysts, systems and methods are described to reduce NO x emissions of an internal combustion engine. In one embodiment, an emissions treatment system for an exhaust stream is provided having a catalyst comprising silver and a platinum group metal on a particulate alumina support, the atomic fraction of the platinum group metal being less than or equal to about 0.25. Methods of manufacturing catalysts are described in which silver is impregnated on alumina particles.