Recent Advances in Electrochemical Hydrogen Production from Water Assisted by Alternative Oxidation Reactions

Abstract

Water electrolysis has been considered a promising avenue for ultrapure hydrogen production. However, the energy efficiency of conventional water electrolysis technologies is severely hampered by the kinetic limitations of the anodic oxygen evolution reaction (OER). Over the past decade, an innovative hybrid water electrolysis strategy of replacing the OER with more facile oxidation reactions and coupling with the cathodic hydrogen evolution reaction (HER) has been developed and demonstrated its utility of addressing the critical challenges in conventional water electrolysis. In this Review, we summarize the recent progress concerning electrochemical hydrogen production from water through hybrid water electrolysis technology, with special emphasis on the selection of electrocatalysts and alternative anodic oxidation reactions as well as the related mechanisms involving in electrochemical reactions. Finally, the current challenges and some perspectives are also discussed for the future development of hybrid water electrolysis technology.

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“…A concept taking all this into consideration will combine both, electrosynthesis of high‐value chemicals in one half cell with the hydrogen evolution as the counter reaction . This in turn can be considered from two perspectives, either by integrating cathodic hydrogen production as a side reaction into oxidative electrosynthesis systems or/and by incorporating oxidative synthesis of certain chemicals instead of oxygen into water electrolysis system.…”

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“…A great opportunity is to substitute the OER by other reactions, that could generate oxidative products of high value in the so‐called hybrid or assisted water electrolysis technology . This approach have advantages, beside the oxidative product, like decreasing the kinetic barrier for the oxidative, while the HER continues to be with high selectivity and purity.…”