Electrochemical deprotonation of halohydrins enables cascading reactions for CO capture and conversion into ethylene carbonate.

Electrochemical processes for CO mitigation can be broadly categorized into two approaches: CO capture via electrochemically generated bases and CO conversion through electrochemical reduction. Recent advancements have been concentrated to developing methods that efficiently capture and release CO or reduce base-CO adducts while regenerating bases for subsequent CO capture. In this study, we introduce an electrochemical strategy that integrates CO capture and conversion through a series of domino reactions initiated by the electrochemical generation of organic bases. This method involves the electrochemical deprotonation of halohydrin molecules, which generate hydrogen and halo-alkoxides that capture CO and spontaneously undergo intramolecular cyclization to yield cyclic carbonates. Direct and indirect Faradaic efficiency of up to 100% is achieved for both hydrogen and ethylene carbonate production, demonstrating highly selective sequential capture and conversion reactions. Our system provides a scalable pathway for synthesizing various cyclic carbonates directly from diluted CO sources.