Improving molten regolith electrolysis with zirconia-based hollow anode technology
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1.
California Institute of Technology
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2.
Jet Propulsion Lab
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3.
Glenn Research Center
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4.
Marshall Space Flight Center
Abstract
Molten regolith electrolysis is a promising in-situ resource utilization technology that targets O2 and metals production through the direct electrolysis of molten lunar regolith. However, there are still challenges associated with molten regolith electrolysis, such as bubble detachment and O2 separation and collection at the anode. A hollow anode, comprised of an oxygen-conducting yttria-stabilized zirconia shell and a platinum current collector, is designed here to address these challenges. Experimental results from an inverted hollow anode reactor successfully demonstrate that molten regolith electrolysis can be performed through a solid electrolyte. The elemental composition of both the cathodic products (primarily Fe and Si) and solidified lunar regolith simulant are reported as a function of electrolysis duration. These observations are supported by a thermochemical model built using FactSage to provide compositions of the cathodic products and solidified regolith simulant with increasing O2 removal. Finally, the behavior of yttria-stabilized zirconia in the hollow anode application is characterized, and provides guidance for the design and operation of a yttria-stabilized zirconia hollow anode to enable integration into a full-scale molten regolith electrolysis reactor.
Copyright and License
© 2025 IAA. Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Acknowledgement
This work was supported by a NASA Space Technology Graduate Research Opportunity (Grant #: 80NSSC22K1184) for K. Yu, K. T. Faber, and L. Reidy. W. West and J. Dominguez were consulted as subject matter experts as part of the NASA Space Technology Graduate Research Opportunity. J. Stokes and B. Harder were supported by NASA Aeronautics Research Mission Directorate's Transformational Tools and Technologies Project. The research was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). The authors gratefully acknowledge Dr. Chi Ma of the Caltech Geology and Planetary Sciences Analytical Facility for his assistance with EBSD and Professor George Rossman for assistance with the confocal Raman microscope. The authors would like to thank Dr. Thierry Caillat at the Jet Propulsion Laboratory for providing the residual gas analyzer used to track O2 production and Dr. Nicholas Heinz at the Jet Propulsion Laboratory for the use of their optical microscopy facilities. The authors would also like to thank Dr. Donald Dornbusch and Dr. Will Huddleston at NASA Glenn Research Center for helpful discussions and support in analyzing the molten regolith electrolysis data. The authors would also like to thank Professor Jean-Philippe Harvey for his assistance with establishing the FactSage thermochemical model used in this study.
Supplemental Material
Supplementary data (DOCX)
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Additional details
- National Aeronautics and Space Administration
- 80NSSC22K1184
- National Aeronautics and Space Administration
- 80NM0018D0004
- Accepted
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2025-06-13
- Available
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2025-06-14Available online
- Available
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2025-06-27Version of record
- Caltech groups
- Division of Engineering and Applied Science (EAS)
- Publication Status
- Published