Enhanced Electrochemical C–N Coupling for Glycine Synthesis via an Active Hydrogen Pump

ABSTRACT Direct electrochemical C–N coupling of abundant carbon and nitrogen feedstocks offers a sustainable route to glycine synthesis, yet achieving high efficiency remains challenging. Here, we develop an In–Bi catalyst by incorporating oxophilic indium (In) into a bismuth (Bi) matrix. During the co‐reduction of oxalic acid and NO 3 − , the In–Bi catalyst delivers an exceptional Faradaic efficiency toward glycine (FE Glycine ) of 83.3% with an industrial‐level current density of 361.3 mA cm −2 , together with a glycine production rate of 4.3 mol h −1 g cat. −1 . It outperforms pristine Bi and previously reported state‐of‐the‐art catalysts. Large‐scale glycine electrosynthesis is further demonstrated over a 10 cm 2 In–Bi electrode, achieving a total current of 1.5 A with FE Glycine of 68.5% and yielding 1.4 g of glycine in 6 h. Mechanistically, oxalic acid and NO 3 − first form glyoxylic acid oxime (GAO). Subsequently, In sites act as an “active hydrogen pump” to accelerate H 2 O dissociation, providing abundant surface‐active hydrogen (*H) for efficient GAO hydrogenation to glycine. Meanwhile, the incorporation of In modulates the electronic structure of the Bi matrix, enhancing GAO adsorption and electron transfer. The synergistic regulation of *H supply and electronic structure accelerates the conversion of GAO to glycine, resulting in superior performance of In–Bi.