Abstract
Electrochemical separations are powerful platforms for the sustainable recovery of critical elements, environmental remediation and downstream processing. However, the recent development of electroseparations has primarily focused on heterogeneous adsorbents, which face the challenge of intermittent electroswing operation. Here we present a redox-mediated electrochemical liquid–liquid extraction separation platform that translates selective single-site binding to a fully continuous separation scheme. A redox-active extractant is molecularly designed with controllable hydrophobicity to maximize organic phase retention. The redox flow design enables fully electrified continuous operation with no external chemical input, achieving the selective recovery of precious metals from multicomponent streams. We demonstrate an atomic efficiency of over 90% and over 100:1 selectivity for practical critical metal leach streams, and 16-fold up-concentration for gold and platinum group metals from varied feedstocks including electronic waste, catalytic converter waste and mining streams. Our work is envisioned as a pathway towards a broader class of industrially applicable liquid–liquid extraction-based electrochemical separations.
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Acknowledgements
This paper is based on work supported by the US Department of Energy, Office of Basic Energy Sciences under award no. DOE DE-SC0021409. This work is also partially supported by the NSF DMREF grant 2323988.
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S.R.C., A.F., J.E. and X.S. conceptualized and designed this work. S.R.C. and A.F. performed the experiments. S.R.C. and X.S. wrote the original paper. X.S. supervised the work and secured the funding. All authors analyzed the data and edited the paper.
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Cotty, S.R., Faniyan, A., Elbert, J. et al. Redox-mediated electrochemical liquid–liquid extraction for selective metal recovery. Nat Chem Eng 1, 281–292 (2024). https://doi.org/10.1038/s44286-024-00049-x
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DOI: https://doi.org/10.1038/s44286-024-00049-x
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