Metallic Ag-BiAg Heterostructured Dendrites Accelerate Carbon–Nitrogen Coupling for Air Plasma-Derived Amino Acid Electrosynthesis

Abstract

Electrochemical C–N coupling driven by renewable electricity provides a sustainable strategy for amino acid synthesis, yet achieving high catalytic efficiency still remains challenging. Herein, a metallic Ag-BiAg heterostructured dendritic electrode is developed by a simple electrodeposition strategy for efficient amino acid electrosynthesis. The optimized catalyst achieves a high glycine Faradaic efficiency of 80.72%, accompanied by a yield rate of 993.3 μmol h–1 cm–2 at −0.9 V vs RHE, outperforming previously reported catalysts. Operando spectroscopic investigations combined with theoretical calculations reveal that the metallic Ag-BiAg heterointerface synergistically optimizes the electronic structure and adsorption behavior of key reaction intermediates, thereby accelerating the generation of the crucial *NH2OH intermediate, enhancing the activation and hydrogenation of glyoxylic acid oxime, and promoting the overall C–N coupling kinetics toward highly selective glycine electrosynthesis. Remarkably, an energy-efficient paired electrosynthesis system integrated with air plasma-derived feedstocks was further constructed, achieving high-performance glycine and formate coproduction over a broad voltage range of 1.2–1.6 V, together with promising long-term stability over 120 h. This work provides a sustainable strategy for air plasma-to-amino acid electrosynthesis through the rational interfacial engineering of dual-site catalytic systems.