Highly dispersed CeO2 for catalytic regeneration of Diesel Particulate Filters

The regeneration behavior of a diesel particulate filter (DPF) wash-coated with nanometric CeO2 particles was investigated focusing on the effect of the soot-catalyst contact. Pore size distribution of the catalyst-loaded filter did not showed significant differences with respect to the starting filter. The effect of the catalyst/soot ration was studied by changing the soot loading. At the lowest soot load explored, the deep penetration of soot particles into the macro-pores of the filter walls and the consequent close touch with highly dispersed ceria result in a large fraction of soot burned via catalytic path at low temperatures. By increasing the soot load, a thicker and thicker soot cake layer is also formed on top of the catalytic walls of the filter. The sook cake is substantially segregated from the catalyst and, as such, is oxidized via thermal path at high temperatures.