Radio Frequency Studies of Soot Loading and Ammonia Storage on a Diesel Particulate Filter with a SCR Catalyst Coating

Abstract

In the exhaust system of some diesel vehicles, the diesel particulate filter (DPF) is loaded with a selective catalyst reduction (SCR) wash coat. This combined catalyst, referred to as a SDPF, serves two functions by trapping soot and by reducing NOx emissions. The latter is accomplished via reactions of NOx with NH3 stored on the SCR wash coat. The NH3 is dosed, as urea, upstream of the SDPF.