Catalysis meets separation: dual-function electrocatalytic membranes for water purification

The increasing water pollution calls for more effective and sustainable treatment technologies. Conventional technologies face critical challenges such as fouling, struggling with emerging micropollutants, and limited mass transfer. Electrocatalytic membranes (ECMs) couple convective transport through a porous membrane-electrode with interfacial electrochemical reactions, enabling simultaneous separation and contaminant transformation in compact process trains. High removal efficiencies are governed by permeation-enhanced mass transfer and current distribution rather than intrinsic catalytic activity. The dominant removal pathway shifts among electrosorption, direct electron transfer, and indirect oxidation. ECMs also reduce fouling via electrostatic repulsion and in-situ redox reactions, suitable for various organic pollutants, including pharmaceuticals and micropollutants, while also enabling resource recovery from wastewater. However, they are limited by durability and secondary burdens, including catalyst deactivation or leaching, pore blockage, catalytic instability, sludge management, and energy-intensive fabrication routes for ceramic ECMs. This review provides a comprehensive overview of ECM fabrication strategies, system configurations, and their multifunctional roles in water treatment. Emerging frontiers include single-atom ECMs that maximize atom utilization and enable tunable reactive-species selectivity, and machine-learning-assisted design frameworks that accelerate multi-objective optimization of catalyst-architecture-operation for durability and by-product control. Standardized metrics linking energy use, current efficiency, by-products, and long-term ageing and life-cycle analyses are essential for scalable deployment of ECM technology. • Electrocatalytic membranes (ECMs) couple filtration with in-pore redox chemistry. • We classify ECM systems and link each configuration to its separation mechanisms. • Electrocatalytic membrane fabrication strategies are assessed. • Industrial-scale deployment is limited by cost, stability, and process complexity. • Challenges and future directions of electrocatalytic membranes are analyzed.