Carbon-efficient carbon dioxide electrolysers

Renewable electricity-powered CO2 electroreduction offers a sustainable route to transform the chemical industry. Here the authors overview four CO2 electrolysis pathways that could be immune from carbonate formation, a major technological barrier. The electroreduction of CO2 (CO2R) is the conversion of CO2 to renewable fuels and feedstocks, a promising technology that could support the transition from fossil to renewable sources in the chemical industry. Today the viability of CO2R technology is limited by carbonate formation via the reaction of reactant CO2 with hydroxides and the energy cost incurred to regenerate the reactant. In this Review, we analyse the literature on four emerging high single pass CO2 conversion approaches: CO2 regeneration from carbonate, CO2R in acidic media, cascade CO2R-COR and CO2R direct from a capture liquid. We analyse each system, describe the challenges associated with each pathway and outline future research directions towards the goal of ensuring that CO2R is viable and thus scalable.