Stainless Steel and Seawater Electrolysis for Hydrogen Production: A Critical Review of Current Evidence and Knowledge Gaps

Stainless steels are increasingly explored as low-cost electrodes for seawater electrolysis, yet their role in hydrogen production remains insufficiently defined due to fragmented data on reaction mechanisms, corrosion behavior, and system-level performance. This review addresses these knowledge gaps by integrating mechanistic insights into HER/OER/ClER in chloride-rich media with a critical assessment of stainless-steel stability under artificial seawater conditions. Literature evidence is combined with experimental results to clarify performance limits, passive-film breakdown, and degradation pathways. The analysis further links electrode behavior with energy efficiency, material durability, techno-economic constraints, and environmental impacts. By connecting fundamental electrochemistry with practical engineering considerations, this review outlines the conditions under which stainless steels can realistically support robust and sustainable seawater-based hydrogen production.