Research progress of chlorine corrosion resistance in seawater electrolysis: Materials and technologies

Electrochemical water splitting for hydrogen production mainly relies on scarce freshwater resources as electrolytic raw materials, leading to the increased costs and constraining its large-scale commercial application. Given the abundance and availability of seawater resources, seawater electrolysis (SWE) has emerged as a promising and low-cost strategy for the production of hydrogen. However, compared to the freshwater electrolysis, seawater electrolysis is more challenging. Especially during the electrolysis, the oxygen evolution reaction (OER) on the anode will be interfered and competed by the chlorine evolution reaction (ClER) as well as more serious chlorine corrosion, resulting in a deactivation and stability decrease of the electrode catalyst. Therefore, researchers are trying to design or develop materials and technologies that improve OER selectivity and resistance to chlorine corrosion. In this brief review, the principle of seawater electrolysis, the competition between OER and ClER and the mechanism of chlorine corrosion are first discussed. Secondly, the design strategy of chlorine-resistant materials for seawater electrolysis and the development of corresponding technologies are recommended. Finally, based on the conclusion, the current challenges and future prospects of developing seawater electrolysis technology for hydrogen production are put forward. © 2024 Elsevier B.V.