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Electrolysis of low-grade and saline surface water

A Publisher Correction to this article was published on 11 May 2021

This article has been updated


Powered by renewable energy sources such as solar, marine, geothermal and wind, generation of storable hydrogen fuel through water electrolysis provides a promising path towards energy sustainability. However, state-of-the-art electrolysis requires support from associated processes such as desalination of water sources, further purification of desalinated water, and transportation of water, which often contribute financial and energy costs. One strategy to avoid these operations is to develop electrolysers that are capable of operating with impure water feeds directly. Here we review recent developments in electrode materials/catalysts for water electrolysis using low-grade and saline water, a significantly more abundant resource worldwide compared to potable water. We address the associated challenges in design of electrolysers, and discuss future potential approaches that may yield highly active and selective materials for water electrolysis in the presence of common impurities such as metal ions, chloride and bio-organisms.

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Fig. 1: The Pourbaix diagram of an aqueous saline electrolyte.
Fig. 2: Leading configurations for water electrolysis.
Fig. 3: Experimental implementation of the alkaline design criterion of saline water splitting.
Fig. 4: Water oxidation activity and stability of oxide catalysts and influence of anionic and cationic contaminations.
Fig. 5: Selective OER catalysts by Cl blocking overlayers.
Fig. 6: Challenges and potential solutions to improve long-term stability of HER in low-grade water.

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W.T., M.F., R.S.E., A.J.C. and P.F. acknowledge financial support from INTERREG Atlantic Area programme (Grant reference EAPA_190_2016). P.F. acknowledges support from Royal Society Alumni programme. F.D., S.D. and P.S. gratefully acknowledge financial support by the German Research Foundation (DFG) through Grant reference number STR 596/8-1 and the federal ministry for economic affairs and energy (Bundesministerium für Wirtschaft und Energie, BMWi) under grant number 03EIV041F. P.S. acknowledges partial funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany´s Excellence Strategy – EXC 2008/1 – 390540038 (zum Teil gefördert durch die Deutsche Forschungsgemeinschaft (DFG) im Rahmen der Exzellenzstrategie des Bundes und der Länder – EXC 2008/1 – 390540038).

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Tong, W., Forster, M., Dionigi, F. et al. Electrolysis of low-grade and saline surface water. Nat Energy 5, 367–377 (2020).

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