Emerging Decoupled Water Electrolysis for Green Hydrogen Production: Current Progress and Future Roadmap

Decoupled water electrolysis (DWE) offers a unique strategy for green hydrogen production by separating the hydrogen and oxygen evolution reactions either in time or space, with the potential for integration to intermittent renewable energy sources. This review highlights the critical assessment of DWE, including the different components used and the operational strategies to accelerate the hydrogen economy. Special emphasis is placed on redox mediator engineering, catalyst innovation, membranes, and next-generation cell architectures to overcome current limitations associated with conventional electrolyzers including efficiency, stability, and cost. The in silico approaches, including density functional theory and molecular dynamics-driven parameter optimization can accelerate DWE by bridging the gap between lab-scale technology development and industrial scale-up, thereby facilitating the rise of DWE as one of the next-generation technologies for green hydrogen production. A visionary roadmap is proposed, showing the pathway from proof-of-concept laboratory studies toward market deployment, with the aim of recognizing DWE as a cornerstone technology for a sustainable, low-carbon hydrogen future. The review is conceptualized based on literature survey and identified research gaps.