Extracting Oxygen from Chang’e-5 Lunar Regolith Simulants
Hao Shi, Peng Li, Zhengshan Yang, Kaiyuan Zheng, Kaifa Du, Lei Guo, Rui Yu, Peilin Wang, Huayi Yin, Dihua Wang
Abstract
Harvesting oxygen and metals from the local resources of the Moon is a key step to advancing outer space exploration. A large amount of oxygen is stored in the lunar regolith in the form of oxides. Many efforts have been devoted to electrochemically splitting oxides to oxygen and metals in molten oxides and molten salts. However, a cheap oxygen-evolution inert anode is still a serious challenge, especially in the supercorrosive molten halides. Herein, we combine a molten CaCl2 electrolyzer that can convert Chang’e-5 lunar regolith simulants to metals and CO2 using a carbon anode and a molten carbonate electrolyzer that can convert the generated CO2 to carbon and oxygen using a cheap Ni11Fe10Cu oxygen-evolution anode. Further, the electrolytic carbon is reused as the anode in the molten CaCl2 electrolyzer, thereby closing the carbon cycle. Hence, the overall electrochemical reaction of the dual-electrolyzer system is to convert lunar regolith to metals and oxygen. More broadly, this system can convert the CO2 generated by humans living on the Moon and Mars to oxygen and carbon materials.