CATALYST, METHOD FOR ITS PREPARATION AND SYSTEM TO REDUCE NOX IN AN EXHAUST GAS STREAM

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 an SCR catalyst comprising silver tungstate on an alumina support. The emissions treatment system may be used for the treatment of exhaust streams from diesel engines and lean burn gasoline engines. An emissions treatment system may further comprise an injection device operative to dispense a hydrocarbon reducing agent upstream of the catalyst.