Development of PdO/Sr₃Fe₂O_{7−<i>δ</i>}/α-Al₂O₃ catalysts for methane combustion

Catalysts, consisting of palladium supported on Ruddlesden-Popper (RP) type Sr₃Fe₂O_7-<i>δ</i> perovskite oxides, were synthesized using co-precipitation and impregnation methods for efficient methane combustion at low temperatures. Achieving effective and stable methane combustion over Sr₃Fe₂O_7-<i>δ</i> perovskite-based catalysts necessitates the suppression of the transformation of the RP-type Sr₃Fe₂O_7-<i>δ</i> perovskite structure supporting active Pd species and the thermal reaction process. In this study, we demonstrated that the use of α-Al₂O₃ as a supporting material in PdO/Sr₃Fe₂O_7-<i>δ</i> /α-Al₂O₃ catalysts significantly improved the surface oxygen species and oxygen vacancy density as well as the structural stability of the composite oxide catalyst. Among the catalysts prepared, the 13 wt% PdO/16 wt% Sr₃Fe₂O_7-<i>δ</i> /α-Al₂O₃ catalyst exhibited the highest catalytic activity for complete methane combustion at a low temperature of 300 °C.