Design Strategy of Corrosion-Resistant Electrodes for Seawater Electrolysis

Abstract

Electrocatalytic water splitting for hydrogen (H2) production has attracted more and more attention in the context of energy shortages. The use of scarce pure water resources, such as electrolyte, not only increases the cost but also makes application difficult on a large scale. Compared to pure water electrolysis, seawater electrolysis is more competitive in terms of both resource acquisition and economic benefits; however, the complex ionic environment in seawater also brings great challenges to seawater electrolysis technology. Specifically, chloride oxidation-related corrosion and the deposition of insoluble solids on the surface of electrodes during seawater electrolysis make a significant difference to electrocatalytic performance. In response to this issue, design strategies have been proposed to improve the stability of electrodes. Herein, basic principles of seawater electrolysis are first discussed. Then, the design strategy for corrosion-resistant electrodes for seawater electrolysis is recommended. Finally, a development direction for seawater electrolysis in the industrialization process is proposed.

Catechol Quinone as an Electron-Shuttling Spot Conjugated to Graphitic Carbon Nitride for Enhancing Photocatalytic Reduction

“…In particular, the oxidation of chloride ions involves a two-eletron transfer, exhibiting faster kinetics, whereas the oxidation of water to oxygen gas involves a four-electron transfer and a high activation barrier, resulting in sluggish kinetics. , Therefore, the chloride oxidation is more favorble, as previously reported for seawater splitting . Furthermore, chloride ions can be oxidized to hypochlorous acid (HClO) or chlorine gas at acidic pH, as shown in eqs and , along with their corresponding standard oxidation potential. − 2 Cl − = Cl 2 + 2 normale − ( + 1.36 V vs NHE ) 2 Cl − + 2 normalH 2 normalO = 2 HClO + 2 normalH + + 2 normale − ( + 1.07 V vs NHE ) …”

Challenges and progress in oxygen evolution reaction catalyst development for seawater electrolysis for hydrogen production

“…) that are doped into existing highly active OER catalysts. 92 Extensive analysis in 23,82,91,[93][94][95][96] has shown that sulphide doping and phosphide doping (anionic dopants) are very promising approaches to enabling stable performance in the presence of Cl − . 4.4.1.2.1.…”

“…This section will investigate anionic (S 2− and P 3− ) and polyanionic dopants (SO 4 2− and PO 4 3− ) that are doped into existing highly active OER catalysts. 92 Extensive analysis in 23,82,91,93–96 has shown that sulphide doping and phosphide doping (anionic dopants) are very promising approaches to enabling stable performance in the presence of Cl − .…”

Catalysts for Direct Seawater Electrolysis: Current Status and Future Prospectives

“…[13][14][15] Direct seawater electrolysis is often carried out in alkaline media to suppress CER. [16][17][18] One additional concern related to the potential challenges associated with direct seawater electrolysis is the chemical stability of the anion exchange membranes (AEM). [19] Also, the presence of contaminants and corrosive ions in seawater can lead to corrosion of the electrodes, bipolar and end flow plates, and membranes over extended periods of operation.…”