(20g) Application of a Glass Catalyst On Wire Mesh to Achieve Low Soot Oxidation Temperature

The most efficient ways to maintain low backpressure during engine operation and minimize fuel penalty due to filter regeneration is through continuous soot oxidation, which can be achieved by employing low temperature soot oxidation catalysts on the DPF. Most continuous regeneration systems, e.g. commercially developed CRT® by Johnson Matthey and HJS, require the engine remain at conditions to give a certain NOx-PM ratio out of the engine, which leads to a high NOx content in the exhaust. In this case, a diesel oxidation catalyst (DOC) has to be added upstream to provide sufficient oxidizing agent (NO2) for soot oxidation because NO2 is a much more effective oxidant than O2. The disadvantage is that, thus far, all of these catalyst systems cannot avoid using platinum group metal (PGM)-based oxidation catalysts (and/or NOx storage catalysts).

In present investigation, a novel K-containing glass catalyst was applied to metal supports for use as a catalyst for diesel soot combustion. The results show that this novel catalytic coating on metal substrates can reduce O2 based soot oxidation temperature to as low as 360oC under loose contact conditions, and offers catalytic stability for long term combustion cycling. This is by far the lowest reported soot oxidation temperature at loose contact condition. This study suggests that continuous soot oxidation is achievable at low NOx/PM ratio environment, which requires less noble metal coating.