Electrochemical Approaches toward CO₂ Capture and Concentration

Abstract

Carbon capture and concentration of low partial pressure CO2 in air and flue gas is a key step in carbon abatement strategies. Traditional CO2 capture methods employ temperature or pressure swings; however, electrochemical swings, in which an applied potential modulates nucleophilicity, are also possible to mediate the capture and release of CO2. In contrast to the breadth of electrochemical CO2 reduction research, electrochemically mediated CO2 capture and concentration is an emerging field. Although some aspects are reminiscent of those in CO2 reduction, like local pH gradients and (bi)carbonate equilibria, ultimately electrochemical CO2 capture and concentration poses its own unique challenges that will benefit from insights from intercalative batteries, redox flow batteries, and biomimetic/-inspired design, among other fields. After an introduction to carbon capture and current chemical strategies, this Review highlights promising emerging electrochemical methods to enable CO2 capture and concentration; specifically discussed are organic redox, transition metal redox, and pH swings. It closes with an outlook and discussion of future research challenges for electrochemically mediated capture.