Nitrate-Stabilized Cu^δ+ Sites Promote Selective CO₂ Electroreduction to Ethanol for Tandem Acetamide Electrosynthesis

Electrosynthesis of acetamide, a multicarbon nitrogenous compound containing C─C─N bonds, from abundant CO₂ and nitrate is important for low-carbon industry. However, the simultaneous electroreduction construction of C─C and C─N bonds is challenging. Herein, we propose a strategy to construct C─C and C─N bonds in tandem at the cathode and anode, respectively. At the cathode, a nitrate-induced dynamic Cu^δ+ site is designed to promote C─C coupling activity from CO₂ reduction to ethanol, which is accompanied by the generation of ammonia from nitrate reduction, with a total Faradaic efficiency of 88.6%. The generated ethanol and ammonia serve as feedstocks for the tandem construction of C─N bonds at the anodic region via a possible nucleophilic attack pathway. We achieve the synthesis of acetamide with a Faradaic efficiency of 71.4% and a yield rate of 0.13 mmol h^-1 cm^-2. The carbon footprint analysis of this tandem strategy revealed net-zero emissions at a carbon intensity of 0.23 kg_CO2e kWh^-1, indicating its sustainable nature from the viewpoint of carbon neutrality.