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 achievement of a 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 simultaneously achieves a high FE (70.25%) and a 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 coupling reactions and is of significant importance for advancing the development of green and efficient amino acid synthesis technologies.