Molten-Carbonate Electrolyzers for Making CO and O2

Electrochemical cells in which molten carbonates would serve as electrolytes have been proposed for use in electrolyzing CO2. The proposal was made in an effort to implement a concept of in situ resource utilization (ISRU) for the exploration of Mars; the basic idea is to generate CO (if needed as a fuel) and O2 (for oxidizing fuel and/or for breathing) by electrolysis of CO2 from the Martian atmosphere. On Earth, molten-carbonate electrolyzers could be used to make breathable O2 for medical use, pure O2 for oxidizing surfaces of semiconductor chips, and CO as a feedstock for synthesis of alcohols and hydrocarbons. In both terrestrial and spacecraft life-support systems, the electrolyzers could be used to regenerate breathable O2 from CO2.