Direct Electrochemical Synthesis of Acetamide from CO₂ and N₂ on a Single-Atom Alloy Catalyst

The electrochemical conversion of carbon dioxide into value-added compounds not only paves the way toward a sustainable society but also unlocks the potential for electrocatalytic synthesis of amides through the introduction of N atoms. However, it also poses one of the greatest challenges in catalysis: achieving simultaneous completion of C-C coupling and C-N coupling. Here, we have meticulously investigated the catalytic prowess of Cu-based single-atom alloys in facilitating the electrochemical synthesis of acetamide from CO₂ and N₂. Through a comprehensive screening process encompassing catalyst stability, adsorption capability, and selectivity against the HER, W/Cu(111) SAA has emerged as an auspicious contender. The reaction entails CO₂ reduction to CO, C-C coupling leading to the formation of a ketene intermediate *CCO, N₂ reduction, and C-N coupling between NH₃ and *CCO culminating in the production of acetamide. The W/Cu(111) surface not only exhibits exceptional activity in the formation of acetamide, with a barrier energy of 0.85 eV for the rate-determining CO hydrogenation step, but also effectively suppresses undesired side reactions leading to various C₁ and C₂ byproducts during CO₂ reduction. This work presents a highly effective approach for forming C-C and C-N bonds via coelectroreduction of CO₂ and N₂, illuminating the reaction mechanism underlying acetamide synthesis from these two gases on single-atom alloy catalysts. The catalyst design strategy employed in this study has the potential to be extended to a range of amide chemicals, thereby broadening the scope of products that can be obtained through CO₂/N₂ reduction.