LAUSR

Abstract Transition metal dimers could exhibit unique electronic properties and better catalytic performance than single metal atom, thus making them attractive to catalyze some chemical reactions, in which the substrate could have prominent influences on their catalytic activity. In this work, the substrate effects of several two-dimensional (2D) carbon-based nanosheets on the adsorption and activation of N2 molecule on their supporting iron dimer (Fe2) were investigated by performing density functional theory (DFT) calculations. Our results showed that the Fe2 cluster can be stably anchored at the defect sites of these 2D carbon-based nanomaterials, thus leading to the accumulation of more positive polarized charges on the supported Fe2 cluster to promote the adsorption and activation of N2 molecule. Interestingly, the g-C3N4 supported Fe2 cluster is predicted to have excellent catalytic activity for converting the activated N2 to ammonia due to the small limiting potential (−0.32 V). Therefore, by choosing a suitable substrate, the Fe2 cluster can be utilized as an ideal electrocatalyst to activate and catalyze the inert N2 molecule.