La0.75Sr0.25Cr0.5Mn0.5O3−δ + Cu composite anode running on H2 and CH4 fuels

La1−xSrxCr1−xMxO3−δ (M = Cr, Fe, V) system has been studied as anode materials for solid oxide fuel cells (SOFCs). The perovskite La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) is stable in both H2 and CH4 atmospheres at temperatures up to 1000°C. However, in the reducing atmospheres of H2 and CH4, its electronic conductivity is greatly reduced from its value in air. We have characterized LSCM as the anode of a SOFC having 250 μm-thick La0.8Sr0.2Ga0.83Mg0.17O2.815 (LSGM) as the electrolyte and SrCo0.8Fe0.2O3−δ (SCF) as the cathode. We report a comparison of the overpotentials at the following anodes: (1) La0.4Ce0.6O1.8 (LDC) + NiO composite in H2, (2) porous LSCM in H2 and CH4, (3) porous LSCM impregnated with CuO in H2 and CH4 and (4) porous LSCM impregnated with CuO and sputtered with Pt in H2 and CH4. An LSCM + CuO + Pt anode gave a maximum power output at 850 °C of 850 mW/cm2 and 520 mW/cm2, respectively, with H2 and CH4 as fuel whereas anode (1) gave 1.4 W/cm2 at 800 °C in H2. There was no noticeable coke formation in CH4 with anodes (2), (3) and (4), which demonstrates that the perovskite oxide is a plausible option for the anode of a SOFC operating with hydrocarbon fuels. We also report the moisture effect in the H2 and CH4 fuel-oxidation process.