CATALYSTS, SYSTEMS AND METHODS TO REDUCE NOX IN AN EXHAUST GAS STREAM

摘要

Catalysts, systems and methods are described to reduce NOx emissions of a n internal combustion engine. In one embodiment, an emissions treatment syst em for an exhaust stream is provided having an SCR catalyst comprising silve r tungstate on an alumina support. The emissions treatment system may be use d for the treatment of exhaust streams from diesel engines and lean burn gas oline engines. An emissions treatment system may further comprise an injecti on device operative to dispense a hydrocarbon reducing agent upstream of the catalyst.