Electrochemical Capture and Release of Carbon Dioxide

Abstract

Understanding the chemistry of carbon dioxide is key to affecting changes in atmospheric concentrations. One area of intense interest is CO<sub>2</sub> capture in chemically reversible cycles relevant to carbon capture technologies. Most CO<sub>2</sub> capture methods involve thermal cycles in which a nucleophilic agent captures CO<sub>2</sub> from impure gas streams (e.g., flue gas), followed by a thermal process in which pure CO<sub>2</sub> is released. Several reviews have detailed progress in these approaches. A less explored strategy uses electrochemical cycles to capture CO<sub>2</sub> and release it in pure form. These cycles typically rely on electrochemical generation of nucleophiles that attack CO<sub>2</sub> at the electrophilic carbon atom, forming a CO<sub>2</sub> adduct. Then, CO<sub>2</sub> is released in pure form via a subsequent electrochemical step. In this Perspective, we describe electrochemical cycles for CO<sub>2</sub> capture and release, emphasizing electrogenerated nucleophiles. As a result, we also discuss some advantages and disadvantages inherent in this general approach.