The discovery of materials for the electrochemical transformation of carbon dioxide into liquid fuels has the potential to impact large-scale storage of renewable energies and reduce carbon emissions. Here, we report the discovery of an electrocatalyst composed of gold nanoparticles on a polycrystalline copper foil (Au/Cu) that is highly active for CO₂ reduction to alcohols. At low overpotentials, the Au/Cu electrocatalyst is over 100 times more selective for the formation of products containing C–C bonds versus methane or methanol, largely favouring the generation of alcohols over hydrocarbons. A combination of electrochemical testing and transport modelling supports the hypothesis that CO₂ reduction on gold generates a high CO concentration on nearby copper, where CO is further reduced to alcohols such as ethanol and n-propanol under locally alkaline conditions. The bimetallic Au/Cu electrocatalyst exhibits synergistic activity and selectivity superior to gold, copper or AuCu alloys, and opens new possibilities for the development of CO₂ reduction electrodes exploiting tandem catalysis mechanisms.

用于将二氧化碳电化学转化为液体燃料的材料的发现有可能影响可再生能源的大规模存储并减少碳排放。在这里，我们报告了在多晶铜箔（Au / Cu）上发现了由金纳米颗粒组成的电催化剂的作用，该催化剂对将CO ₂还原为醇具有很高的活性。在低电势下，与甲烷或甲醇相比，金/铜电催化剂对形成具有C–C键的产品的选择性要高出甲烷或甲醇100倍以上，这在很大程度上有利于醇的生成而不是碳氢化合物的生成。电化学测试和运输模型的结合支持了以下假设：CO ₂金的还原会在附近的铜上产生高的CO浓度，在局部碱性条件下，CO会进一步被还原为醇，例如乙醇和正丙醇。双金属Au / Cu电催化剂具有优于金，铜或AuCu合金的协同活性和选择性，并为利用串联催化机理开发CO ₂还原电极提供了新的可能性。