An optimal NOx assisted abatement of diesel soot in an advanced catalytic filter design

Two standard soot catalytic filter configurations and a so-called TU Delft (TUD) catalytic filter have been investigated in laboratory equipment to evaluate its potential as diesel soot exhaust catalytic filter. The first configuration, where Pt/SiC foam catalyst was placed upstream of soot loaded on SiC foam, showed the lowest NO2-slip and the lowest soot oxidation rate. In the second configuration, soot was loaded on Pt/SiC foam. This gives rise to a higher soot oxidation rate at the expense of a higher NO2-slip. An improvement on the utilisation of NO2 with lower NO2-slip has been observed in the TUD catalytic filter in addition with the highest soot oxidation rate. As with all diesel particulates filter TUD catalytic filter up to 10% CO (around 50 ppm) is formed as soot combustion product, whereas for the miniaturisation of the commercially available continuously regeneration trap (CRT) system at the same diesel soot oxidation rate 120–140 ppm CO is observed. Calculations to assess the potential application of the system showed that the system is promising.