Low cost catalysts for regeneration of diesel particulate filters

A range of perovskites including the substituted and promoted perovskite type catalytic materials have been designed and synthesized using various techniques. In this work we have studied the catalytic activities of a praseodymium substituted La0.8Pr0.2MnO3 and La0.7K0.1Pr0.2MnO3 based perovskites synthesized by coprecipitation, which is further improved by incorporation of alkali metals like potassium (K). Potassium substituted La0.7K0.1Pr0.2MnO3 perovskite shows good catalytic activity for soot/carbon oxidation probably promotional effect of potassium. The La0.7K0.1Pr0.2MnO3 showing Tinitial at 300oC and Tfinal at 510oC, which is almost 110oC lower than the noncatalyzed reaction. The synergetic effects of Pr incorporation in perovskite and presence of a small amount of potassium appears to be responsible for the high soot oxidation activity of these perovskite type materials. The La0.7K0.1Pr0.2MnO3 type catalyst can also be synthesized directly on commercially available diesel particulate filters (DPF). Suitability of perovskite type catalysts for flow-through type DPF and their improved stability with low sulfur diesel add to their potential for their application in regeneration of DPF. These studies should actually pave the way towards practical application of this class of catalysts in the field of diesel exhaust emission control.