Heterogeneous single-cluster catalysts(Mn3,Fe3,Co3,and Mo3)supported on nitrogen-doped graphene for robust electrochemical nitrogen reduction

Electrochemical nitrogen reduction reaction(NRR)is one of the most promising alternatives to the traditional Haber-Bosch process.Designing efficient electrocatalysts is still challenging.Inspired by the recent experimental and theoretical advances on single-cluster catalysts(SCCs),we systematically investigated the catalytic performance of various triple-transition-metal-atom clusters anchored on nitrogen-doped graphene for NRR through density functional theory(DFT)calculation.Among them,Mn₃-N4,Fe₃-N4,Co₃-N4,and Mo₃-N4 were screened out as electrocatalysis systems composed of non-noble metal with high activity,selectivity,stability,and feasibility.Particularly,the Co₃-N4 possesses the highest activity with a limiting potential of-0.41 V through the enzymatic mechanism.The outstanding performance of Co₃-N4 can be attributed to the unique electronic structure leading to strong π backdonation,which is crucial in effective N₂ activation.This work not only predicts four efficient non-noble metal electrocatalysts for NRR,but also suggest the SCCs can serve as potential candidates for other important electrochemical reactions.