Electrochemical Carbon Dioxide Capture and Release with a Redox-Active Amine

Anthropogenic carbon dioxide (CO₂) emission from the combustion of fossil fuels is a major contributor to global climate change and ocean acidification. The implementation of carbon capture and storage technologies has been proposed to mitigate the buildup of this greenhouse gas in the atmosphere. Among these technologies, direct air capture is regarded as a plausible CO₂ removal tool whereby net negative emissions can be achieved. However, the separation of CO₂ from air is particularly challenging due to the ultradilute concentration of CO₂ in the presence of high concentrations of dioxygen and water. Here, we report a robust electrochemical redox-active amine system demonstrating a high electron utilization (i.e., mole of CO₂ per mole of electrons) of up to 1.25 with the capture of two CO₂ molecules per amine in an aqueous solution with a work of 101 kJ_e per moles of CO₂. The capture of CO₂ directly from ambient air as the feed gas presented an electron utilization of 0.78.