Electrolyzing Outside the Box: Non-Traditional Approaches to Electrochemical Water Splitting

Water electrolysis is a key process for sustainable hydrogen production. At present, the most mature and widely investigated techniques are limited to four main methods: alkaline water electrolysis, proton exchange membrane (PEM) electrolysis, anion exchange membrane (AEM) electrolysis, and solid oxide electrolysis. However, the quest for enhanced efficiency, reduced costs, and sustainable energy integration has spurred the development of unconventional design approaches for water splitting. This review explores the latest advancements in non-traditional water electrolysis techniques, including atmosphere water electrolysis, supercritical water electrolysis, external field-assisted electrolysis, electrolysis with ionic liquids, and decoupled water electrolysis. Each method offers unique benefits, such as the utilization of alternative energy sources, improved reaction kinetics, and the potential for integration with renewable energy systems. By examining the principles, advantages, and challenges of these innovative approaches, this review aims to provide a comprehensive understanding of how unconventional methods are reshaping the landscape of hydrogen production and how the insights gained from these emerging techniques can play a critical role in advancing the global transition to a hydrogen-based energy economy.