Direct methane oxidation on La1−xSrxCr1−yFeyO3−δ perovskite-type oxides as potential anode for intermediate temperature solid oxide fuel cells

Abstract La 1− x Sr x Cr 1− y Fe y O 3− δ ( x  = 0, 0.1, 0.15, 0.2; y  = 0, 0.3, 0.5) perovskite-type oxide powders were synthesized by solution combustion synthesis and characterized by X-ray diffraction, X-ray photoelectron spectroscopy and H 2 -temperature programmed reduction. Selected compositions were studied by CH 4 -temperature programmed reduction in the absence and in the presence of H 2 S. Temperature programmed oxidation and structural characterizations were performed in order to discriminate the nature of residual deposits on the catalyst surface. The study about reduction in different methane-based mixture revealed that total and partial methane oxidation occurred in the range ∼450–1000 °C independently of methane concentration. The H 2 S influence on methane oxidation was evaluated and experiments in CH 4 /H 2 S gas mixture indicated that La 0.9 Sr 0.1 Cr 0.7 Fe 0.3 O 3− δ oxidized CH 4 to CO 2 and CO, as well as H 2 S to SO 2 . La 0.9 Sr 0.1 Cr 0.7 Fe 0.3 O 3− δ was therefore identified a potential anode material for intermediate temperature solid oxide fuel cells directly fed with CH 4 in the presence of H 2 S.