High-rate mass transfer in a mesoporous catalyst with atomically dispersed cobalt sites enables efficient electrochemical synthesis of glycine

Abstract

To replace toxic, cumbersome conventional routes, green electrosynthesis of glycine is a hotspot. However, due to the complexity of multi‑electron/proton transfer, simultaneous attainment of high Faradaic efficiency (FE) and high production rate in the electrochemical synthesis of glycine remains elusive. To overcome this bottleneck, this work proposes a novel strategy that synergistically enhances mass transport and the stability of active sites. By constructing a carbon support with a high specific surface area and mesoporous structure, efficient mass transport channels are established for reactants, significantly improving their diffusion toward active sites. In addition, atomically dispersed CoN₄ centers prevent Co aggregation, affording stable sites for continuous selective C-N coupling. The atomically dispersed cobalt catalyst supported on nitrogen-doped carbon (Co-N-C-700) prepared based on the above strategy achieves simultaneous high FE (70.25%) and high production rate (907.1 μmol h-1 cm-2) for preparation of glycine at -0.85 V vs RHE. The catalyst also exhibits good generality for the synthesis of a variety of amino acids. This study provides a generalizable design concept for addressing mass transport limitations and active site stability in complex C-N coupuling reactions, and is of significant importance for advancing the development of green and efficient amino acid synthesis technologies.