Self-propagating High-temperature Synthesis of La1−xSrxMnyFe1−yO3 Perovskites for Soot Combustion Catalyst

Abstract

AbstractThe La1−xSrxMnyFe1−yO3 samples of perovskite-type oxides were synthesized by Self-propagating High-temperature Synthesis (SHS) method. In this study, first, we synthesized B-site substituted perovskite-type oxides, LaMnxFe1−xO3. The SHS method successfully synthesized LaMnxFe1−xO3. The most active composition for soot combustion among synthesized samples of LaMnxFe1−xO3 was x = 0.4, LaMn0.4Fe0.6O3, from model-soot combustion experiment with TG/DTA analysis. We then examined the effect of A-site substitution by Sr on LaMn0.4Fe0.6O3 perovskite. The SHS of La1−xSrxMn0.4Fe0.6O3 was successfully ignited, propagated and completed. XRD peaks of perovskite-type oxide phase was detected in all the synthesized La1−xSrxMn0.4Fe0.6O3 but unreacted material, SrCO3, was also detected in the sample above x = 0.6 from XRD analysis. The soot combustion activity of Sr-doped LaMn0.4Fe0.6O3 was not enhanced according to the impurity in the samples. The most active composition among synthesized samples of La1−xSrxMnyFe1−yO3 was LaMn0.4Fe0.6O3 which exhibited lower activation energy than conventional Pt/Al2O3 catalyst, that is, LaMn0.4Fe0.6O3 synthesized by SHS method had superior soot combustion activity despite its relatively small specific area.