Advances and Challenges in Membrane-Based Electrochemical Reactors for CO₂ Capture: A Mini-Review

Electrochemical CO₂ capture technologies are increasingly recognized for their flexibility, ability to mitigate CO₂ emissions from various sources, and potential for integration with renewable power sources. Despite their promise, most studies remained at the proof-of-concept stage due to their limitations in stability, CO₂ sorption efficiency, and capacity. This mini-review focuses on recent developments and energy-efficiency comparisons of membrane-based electrochemical reactors for CO₂ capture. We explore the mechanisms and chemical systems underlying pH swing, Faradaic electro-swing, and capacitive swing processes. Additionally, we compare these approaches in terms of applicable systems and energy consumption. We identify key limitations, such as nonideal membrane properties, undesirable electrode reactions, and limitations of redox-active carriers. Finally, we highlight areas for improvement and propose research directions to advance this emerging field, in pursuit of being more competitive and efficient for practical CO₂ capture applications.