Nature Energy, Published online: 15 September 2026; doi:10.1038/s41560-026-02130-6

Given its abundance, seawater is an attractive feedstock for hydrogen production, but direct electrolysis is hindered by side reactions and corrosion. Here the authors couple alkaline electrolysis with low-temperature desalination, using waste electrolyser heat to distil seawater into a fresh water feed, enabling stable, scalable performance.