Development of PdO/Sr3Fe2O7−δ/α-Al2O3 catalysts for methane combustion

Abstract

Catalysts, consisting of palladium supported on Ruddlesden–Popper (RP) type Sr₃Fe₂O_7−δ 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−δ perovskite-based catalysts necessitates the suppression of the transformation of the RP-type Sr₃Fe₂O_7−δ 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−δ/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−δ/α-Al₂O₃ catalyst exhibited the highest catalytic activity for complete methane combustion at a low temperature of 300 °C.