Promotion effect of Au on perovskite catalysts for the regeneration of diesel particulate filters

Four LaBO3 perovskite catalysts (B = Cr, Mn, Fe and Ni), also supporting 2% by weight of gold, were prepared via the so-called Solution Combustion Synthesis (SCS) method, and characterized by means of XRD, BET, FESEM-EDS, TEM, O2-TPD and CO-TPR analyses. The performance of these catalysts, in powder form, was evaluated towards the simultaneous oxidation of soot and CO. The 2 wt.% Au–LaNiO3 showed the best performance with a peak carbon combustion temperature of 431 °C and a half CO conversion of 156 °C. The same nano-structured catalyst, deposited by in situ SCS directly over a SiC filter and tested on real diesel exhaust gases, fully confirmed the encouraging results obtained with catalyst powder.