Electrochemical capture and release of carbon dioxide

Understanding the chemistry of carbon dioxide is key to affecting changes in atmospheric concentrations. One area of intense interest is CO₂ capture in chemically reversible cycles relevant to carbon capture technologies. Most CO₂ capture methods involve thermal cycles in which a nucleophilic agent captures CO₂ from impure gas streams (e.g., flue gas), followed by a thermal process in which pure CO₂ is released. Several reviews have detailed progress in these approaches. A less explored strategy uses electrochemical cycles to capture CO₂ and release it in pure form. These cycles typically rely on electrochemical generation of nucleophiles that attack CO₂ at the electrophilic carbon atom, forming a CO₂ adduct. Then, CO₂ is released in pure form via a subsequent electrochemical step. In this Perspective, we describe electrochemical cycles for CO₂ capture and release, emphasizing electrogenerated nucleophiles. We also discuss some advantages and disadvantages inherent in this general approach.