CO₂ Capture via Electrochemical pH-Mediated Systems

The rising atmospheric CO₂ concentrations necessitate energy-efficient, modular, and low-cost approaches to CO₂ capture. Conventional CO₂ capture methods swing the CO₂ absorption capacity by modulating the temperature or pressure, rendering them energy intensive. Electrochemical CO₂ capture technologies could utilize renewable electricity to modulate the CO₂ absorption capacity electrochemically, enabling viable energetics, capture capacities, modularity, and facile implementation. The electrified route can achieve CO₂ capture from point sources and the atmosphere without requiring heat and pressure. This Review provides an overview of emerging electrochemical pH-mediated CO₂ capture approaches: electrolysis, bipolar membrane electrodialysis and electrodeionization, and proton-coupled electron transfer mediators. It describes the operating principles, materials, components, and system/process configurations, discusses the recent advances, milestones, and remaining challenges, and provides a comparative analysis of capture technologies. The Review ends with the outlook that underscores the research gaps and provides research directions for performance, efficiency, and practicality advancements.