Graphitic Carbon Nitride Supported Trimeric Metal Clusters as Electrocatalysts for N2 Reduction Reaction

As a cleaner and more energy-efficient alternative, the electrochemical reduction of N2 to NH3 under mild conditions has emerged as a promising avenue for environmental protection. However, developing catalysts with both high activity and selectivity has been a challenging task. The advent of atomically dispersed catalysts is revolutionizing the field of catalysis. Drawing inspiration from the successful fabrication of Ru trimer on graphitic carbon nitride (g-C3N4) nanosheets, herein, we adopted a series of trimeric metal clusters anchored on g-C3N4 monolayer (TM3@g-C3N4, TM = 3d, 4d and 5d transition metal atom), as well as utilized the criteria range to describe the stability, activity, energy cost and selectivity of supported trimers for N2 reduction reaction based on ab initio calculations combined with multi-level screening strategies. Finally, 5 candidate TM3@g-C3N4 (TM = Rh, Ru, V, Mo, and Re) exhibits decent catalytic activity with limiting potential ranging of –0.50 ~ –0.02 V. These spatially confined triatomic metal centers demonstrated proficiency in activating N2 molecules while exhibiting tunable surficial reactivity through modulation of the metal elements and interfacial electron coupling between trimers and underlying substrates. More importantly, a structure–activity relationship was established, which provides crucial insights for precise design of highly efficient atomically-precise catalysts at an atomic level for hydrogen fuel storage.