Efficient Glycine Electrosynthesis via CO₂‐Recyclable Hydrogen Donation on Pb/Pb₇Bi₃ Heterointerfaces

Abstract Electrochemical synthesis has emerged as a sustainable platform in constructing C─N bonds for amino acid production. Glycine, a particularly valuable target compound, continues to experience escalating global demand, yet achieving simultaneous high efficiency and operational stability remains a persistent challenge. Herein, we demonstrate a CO 2 ‐mediated strategy for glycine electrosynthesis using oxalic acid and N 2 /nitrate as feedstocks. By using Pb/Pb 7 Bi 3 ‐CO 2 catalytic system, a very high glycine Faradaic efficiency (FE) of 91.8% with durable stability over 120 h could be achieved. Moreover, when using nonthermal plasma‐activated N 2 as the nitrogen source, the glycine production rate could maintain at 94.4 µmol h −1 cm −2 with N‐selectivity as high as 93.2%. Mechanistic investigations combining experiments and theoretical calculations reveal that CO 2 undergoes facile protonation on the Pb/Pb 7 Bi 3 heterointerfaces to form * OCOH intermediate, which donates hydrogen for the reduction of oxalic acid and nitrate into glyoxylic acid and NH 2 OH, respectively, while CO 2 is simultaneously regenerated. Notably, hydrogenation via the * OCOH intermediate significantly lowers the energy barriers compared to direct protonation, thereby promoting the subsequent spontaneous C─N bond formation and enabling highly efficient electrosynthesis of glycine.