Soot oxidation in low-O2 and O2-free environments by lanthanum-based perovskites: structural changes and the effect of Ag doping

The use of La-based, Cu (LCO), Mn (LMO) and Fe (LFO) perovskites doped with Ag was studied for potential application as cGPF soot oxidation catalysts. Special emphasis was placed on the effect of the soot, reaction gas composition, changes in rich/lean conditions and the resulting physicochemical changes in the catalyst and their reversibility. The use of a catalyst reduced the soot oxidation temperature significantly in a low-O-2 environment and with Ag doping the soot oxidation temperature was decreased by 170 degrees C in loose contact and 230 degrees C in tight contact compared to uncatalyzed oxidation. For the soot oxidation in an O-2-free environment, the highest oxygen storage capacity was found for LCO and LCAO (1 mol O per mol(cat)). The release of such a high amount of O and reduction of Cu2+ to Cu-0 was accompanied by the loss of perovskite structure (LCO -> Cu/La2O3), which could be reversed following exposure to a high temperature low-O-2 environment.

Automated summary

The study explored the potential use of La-based perovskites doped with Ag as cGPF soot oxidation catalysts, focusing on the effects of different conditions on the catalyst and soot oxidation. Results showed a significant reduction in soot oxidation temperature and high oxygen storage capacity in certain catalysts under specific conditions.