Efficient CO₂ Electroreduction to Ethanol by Cu₃Sn Catalyst

Electrochemical carbon dioxide reduction to ethanol suggests a potential strategy to reduce the CO₂ level and generate valuable liquid fuels, while the development of low-cost catalysts with high activity and selectivity remains a major challenge. In this work, a bimetallic, low-entropy state Cu₃Sn catalyst featuring efficient electrocatalytic CO₂ reduction to ethanol is developed. This low-entropy state Cu₃Sn catalyst allows a high Faradaic efficiency of 64% for ethanol production, distinctively from the high-entropy state Cu₆Sn₅ catalyst with the main selectivity toward producing formate. At an industry-level current density of −900 mA cm⁻², the Cu₃Sn catalyst exhibited excellent stability for over 48 h in a membrane-electrode based electrolyzer. Theoretical calculations indicate that the high ethanol selectivity on Cu₃Sn is attributed to its enhanced adsorption of several key intermediates in the ethanol production pathway. Moreover, the life-cycle assessment reveals that using the Cu₃Sn electrocatalyst, an electrochemical CO₂-to-ethanol electrolysis system powered by wind electricity can lead to a global warming potential of 120 kg_CO2-eq for producing 1 ton of ethanol, corresponding to a 55% reduction of carbon emissions compared to the conventional bio-ethanol process.