Autonomous Exploitation of Reaction Pathways for Electrochemical C–N Coupling on Single-Atom Catalysts

Abstract

Electrochemical C–N coupling between CO₂ and N-containing small molecules is a promising strategy to close both the carbon and nitrogen loops to support the establishment of a net-zero carbon economy. However, the intricate reaction network and the contentious C–N coupling mechanism hinder the development of efficient electrocatalysts for industrial applications. Herein, we develop a graph-based approach to enable autonomous analysis of the C–N coupling mechanism for coreduction of CO₂ and NO₃^– on single-atom catalysts (SACs). 1400 potential intermediates and 2490 C–N coupling modes are investigated based on the Cu-N₄-C prototypical catalyst. We demonstrate that N-containing species with a higher reduction degree are more likely to undergo C–N coupling and the initial coupling of the C–N bond tends to occur on CO₂. It is revealed that the hydrogenation energies of *NH₂ and CO₂, as well as their coupling energies, can serve as key indicators for catalyst recommendation. Using this approach, SACs with Mo, W, or Sb metal centers are identified as promising electrocatalysts for C–N coupling. This work presents a paradigm for automatically exploring the mechanisms of complex electrocatalytic reactions and offers a strategy for predicting highly active and selective SACs.