Toward solvent-free continuous-flow electrochemically mediated carbon capture with high-concentration liquid quinone chemistry

The recent interest in electrochemical methods of carbon capture has thus far focused either on static adsorbent-type electrodes, which require complex gas distribution and release engineering, or aqueous flowing systems, which allow capture over large, distributed areas and release from a centralized point, but require large amounts of water. Here, we advance a concept for a flowing, electrochemically mediated carbon capture process by utilizing redox-active molecules that are liquid at room temperature, avoiding the need for large water feeds. To demonstrate the potential of this concept, we employed a liquid quinone sorbent with added glyme to aid in salt solubilization coupled to a ferrocene-derived counter electrolyte. We achieved good electrochemical stability and continuous capture and release of CO₂ in a full bench scale process. Our concept for continuous-flow electrochemical CO₂ capture suggests many areas for further study, particularly the need for novel cell concepts and designs.