(La_0.75Sr_0.25)0.95Mn_0.5Cr_0.5O₃ as the Cathode of Solid Oxide Electrolysis Cells for High Temperature Hydrogen Production from Steam

Ni/YSZ cathodes are generally utilised for steam electrolysis; however such electrodes can only operate under reducing conditions. In an atmosphere with low content of H-2 or without H2, especially under low current conditions, cathodes based on (La0.75Sr0.25)(0.95)Mn0.5Cr0.5O3 (LSCM) provide a promising alternative. Solid Oxide Electrolysis Cells with LSCM cathodes were tested under external potential load at temperatures between 750 degrees C and 1000 degrees C using 3% steam/Ar/4% H-2 and 3% steam/Ar, and promising polarisation impedance data were obtained in both atmospheres, especially in the gas without H-2. I-V curves from LSCM cells in 3% steam/Ar have sigmoidal shape indicative of chemical changes in the LSCM occurring in addition to electrolysis. Despite these features, considerably improved performance is found compared to Ni-based electrodes in low hydrogen conditions.