Exploring hybrid seawater electrolysis with anodic oxidation reactions (AORs): recent progress and prospects

Abstract

The major obstacle in electrocatalytic seawater splitting (ESS) is the electro-oxidation of dissolved ions at the anode, which causes significant electrode corrosion and competes with the oxygen evolution reaction (OER), ultimately lowering efficiency. Although various electrocatalysts have been employed, achieving high current densities for seawater splitting without triggering side reactions remains a challenging task. Therefore, researchers have substituted oxygen evolution reaction (OER) in seawater electrolysis with various anodic oxidation reactions (AORs) including organic/inorganic compounds. This development of a hybrid seawater electrolysis system enhances hydrogen production at the cathode and generates high-value products at the anode. This approach is crucial in preventing side reactions like chloride oxidation reaction (ClOR), OER, and catalyst corrosion. In recent years, this technique has been extensively explored by researchers to address the challenges of seawater electrolysis and improve its efficiency. A series of electrocatalysts have been investigated for hybrid seawater electrolysis. Despite significant progress in this emerging area, there is no dedicated review available in the literature for hybrid seawater electrolysis. This review aims to fill this gap by focusing systematically on the recent progress and development of electrocatalysts specifically designed for hybrid seawater electrolysis. This review explores the structure–property–performance relationships of electrocatalysts, supported by pioneering examples. The impact of structure, morphology, and electronic properties of the catalysts on hybrid seawater electrolysis performance has been described in detail. Additionally, we discuss future advancements and challenges associated with the ongoing research into hybrid seawater electrolysis.