Effects of manganese substitution at the B-site of lanthanum-rich strontium titanate anodes on fuel cell performance and catalytic activity

Sr0.4La0.6Ti1−xMnxO3−δ with rhombohedral structure has been investigated in terms of their electrochemical performance, redox stability, and electro-catalytic properties for solid oxide fuel cell anodes. The performance of Sr0.4La0.6Ti1−xMnxO3−δ anodes for solid oxide fuel cells strongly depends on the Mn substitution at the B-site of the perovskites. Electrical conductivity of Sr0.4La0.6Ti1−xMnxO3−δ increases with increasing Mn content. X-ray photoelectron spectroscopy analysis reveals that the amount of Mn3+ and Ti3+, which is an electronic charge carrier, increases with Mn doping. The reduced anode powders with high Mn/Ti ratio show oxygen storage capability and a low carbon deposition rate. Linear thermal expansion coefficients of Sr0.4La0.6Ti1−xMnxO3−δ anodes range from 9.46×10−6 K−1 to 11.3×10−6 K−1. The maximum power densities of the single cell with the Sr0.4La0.6Ti0.2Mn0.8O3−δ anode in humidified H2 and CH4 at 800 °C are 0.29 W cm−2 and 0.24 W cm−2, respectively.