Mini Review on Electrocatalyst Design for Seawater Splitting: Recent Progress and Perspectives

Abstract

Production of renewable hydrogen energy by water electrolysis is an effective method to reduce carbon emissions. In comparison to freshwater, seawater is a more suitable raw material for electrolysis thanks to its abundant reserves. However, the reported catalysts are not suitable for large-scale commercial application as a result of the reduction of catalyst stability and activity within complex natural seawater. To better promote the rational design of electrocatalysts and tackle the challenges of seawater splitting, this mini review summarized recent advances in rational design electrocatalysts for seawater splitting, including constructing a hierarchical structure, decorating a corrosion resistance layer, and introducing a charge redistribution within the system. Afterward, a perspective in the development of large-scale seawater electrolysis for hydrogen production is also proposed.

Recent Advances and Perspectives of Nanostructured Amorphous Alloys in Electrochemical Water Electrolysis

“…At the same time, in order to establish the relationship between the dynamic changes of active sites and the electrocatalytic efficiency, and obtain the dynamic evolution information on catalysts, reactants, intermediates and products, it is necessary to develop and establish in situ characterization technology, especially in the liquid phase. Future research on electrocatalysis should not be limited to the development of excellent electrocatalysts but should also look at the whole electrolysis system, and actively close to practical industrial applications. − …”

IrOx Nanoclusters Modified by BaCO3 Enable ″Two Birds with One Stone″ in Solar-Driven Direct Unbuffered Seawater Electrolysis

“…However, currently, electrocatalytic hydrogen production (acid and alkaline) relies heavily on pure freshwater, which is still a scarce resource as only 0.5% of the earth’s water is available as freshwater. In contrast, 96.5% of the total water reserves of the planet is seawater; thereby, direct seawater electrolysis (DSE) appears to be more promising. − The reactions at the anode of DSE will occur in parallel with the chlorine evolution reaction (CER) and oxygen evolution reaction (OER) due to the presence of chloride ions in seawater (∼0.5 M NaCl). In fact, little chlorine gas will be formed because the produced Cl 2 will quickly react with water to form hypochlorous acid (eq ) and then partially dissociate into hypochlorite anion (eq ).…”

Strategies of Anode Design for Seawater Electrolysis: Recent Development and Future Perspective

“…Although the electrochemical oxidation of Cl − anions produced precious products, that is, hypochlorite, hypochlorous acid, and Cl 2 gas, they alter the solution conditions and cause the severe corrosion of electrodes. [ 17 ] Hence electrodes should be selective for OER to sustain their performance. The second challenge is the presence of different non‐innocent ions in seawater that further hampers the OER kinetics.…”