High Surface Area Iridium Anodes and Melt Containers for Molten Oxide Electrolysis

Direct electrochemical reduction of molten regolith is the most attractive method of oxygen production on the lunar surface, because no additional chemical reagents are needed. The process is proven on a laboratory scale, but the cathode-anode system and melt containers need to be improved for practical applications. The electrochemical processing of molten oxides requires high surface area inert anodes. Such electrodes need to be structurally robust at elevated temperatures (1400-1600oC), resistant to thermal shock, have good electrical conductivity, resistant to attack by molten oxide (silicate), electrochemically stable, and support high current density. Iridium is a proven material for this application. Innovative concepts for large scale, high surface area iridium anodes and long life, self-heating containers for the melts are proposed. The result of this program will be the development, manufacture, and test of high surface area iridium anodes and melt containers for molten oxide electrolysis to produce oxygen.