Toward energy‐efficient and circular bipolar membrane electrodialysis: Catalyst design, H ⁺ leakage mitigation, and alkali valorization

Abstract Bipolar membrane (BPM) is a special type of ion exchange membrane consisting of a cation exchange membrane (CEM), an anion exchange membrane (AEM), and a catalytic layer (CL), which can generate H + and OH − through the water dissociation (WD) mechanism. This unique property makes bipolar membrane electrodialysis (BMED) a green ion separation technology with broad applications in acid–base recovery, zero liquid discharge of high‐salinity wastewater, and energy conversion and storage. Based on the elucidation of the WD mechanism of bipolar membranes and the various preparation methods of such membranes, this paper summarizes the applications of various novel WD catalysts in reducing the WD overpotential, analyzes the factors affecting H + leakage in BMED processes, and clarifies the corresponding optimization strategies. In addition, the applications of the alkaline solution produced by BMED in carbon capture and valuable constituents recovery are discussed, highlighting the great potential of BMED in building a circular economy and achieving sustainable development. Future research directions include the development of novel and efficient WD catalysts, advanced anion membrane materials with balanced hydrophilic‐hydrophobic properties, and closed‐loop resource integration systems to achieve low‐energy consumption BMED applications.