Surface properties and catalytic performance in methane combustion of La0.7Sr0.3Fe1-yGayO3-δ perovskite-type oxides

The perovskite-type oxides La0.7Sr0.3Fe1-yGayO3-delta (y = 0, 0.3, 0.5, 0.7 and 1), usually applied as oxygen-permeable membrane materials, were investigated as catalysts for the catalytic combustion of methane. The structure and properties of these catalysts were characterized by XRD, BET, XPS and TPR techniques. The catalytic activities were strongly influenced by the Fe contents of the mixed oxides, which was examined in relation to the structure and surface characteristics and may be correlated with their surface oxygen species and redox properties. The optimized catalytic performance was observed for La0.7Sr0.3Fe0.7Ga0.3O3-delta with the highest methane conversion of 91% at 600 degrees C and the thermal stability test was also described. (C) 2008 Elsevier B.V. All rights reserved.