Triple atom catalyst with ultrahigh loading potential for nitrogen electrochemical reduction

One of the key challenges with atomic catalysts (single, double, and triple atom catalysts) is relatively low loading of active materials, resulting in low mass or volume activity of catalysts, which hinders their rapid development in the catalytic field. Herein, by density functional theory (DFT), we explore a series of atomic catalysts with the substrate of a heterostructure of graphdiyne and graphene (GDY/Gra) for nitrogen reduction reaction (NRR). The theoretical mass loading of active metal atoms can exceed 35.0 wt% in the triple atom catalyst (TAC), which could be infinitely close through the optimal substrate and the suitable precursors in experiments. Among these designed atomic catalysts, Fe3-GDY/Gra with a theoretical mass loading of 35.8 wt% shows an outstanding catalytic activity for electrocatalytic NRR with the potential of -0.26 V vs. the reversible hydrogen electrode (RHE). Moreover, proposed TACs show better catalytic activity for NRR than single atom catalysts (SACs) and double atom catalysts (DACs) due to the unique properties of M3 (M = Mn, Fe, Co, Ni) active sites, which provide more electrons for activating N2, but also show a weak adsorption to allow for an easier release products. These findings provide a new strategy for designing atomic catalysts with high loading, high stability, and high activity.