Deere & Company
Exhaust gas treatment system and method with four-way catalyzed filter element

Abstract:

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway configured to receive exhaust gas from the internal combustion engine, a first injector configured to selectively introduce a first reductant into the exhaust gas pathway in response to a sensed temperature of the exhaust gas being within a predetermined temperature range, and a first treatment element positioned within the exhaust gas pathway downstream of the first injector. The first treatment element includes a selective catalytic reduction (SCR) layer, a porous filter substrate, and a precious metal catalyst layer. The system also includes a second injector configured to introduce a second reductant into the exhaust gas pathway downstream of the first treatment element and a second treatment element positioned within the exhaust gas pathway downstream of the second injector. The second treatment element includes a SCR element.