Computational Evaluation of Electrocatalytic Nitrogen Reduction on TM Single-, Double-, and Triple-Atom Catalysts (TM = Mn, Fe, Co, Ni) Based on Graphdiyne Monolayers

Low-cost and efficient electrocatalysts are urgently required for the N-2 reduction reaction (NRR) to produce NH3 under ambient conditions. By using first-principles calculation, we systematically investigated the NRR catalytic activity of the transition metal (TM, including Mn, Fe, Co, and Ni) monomer-, dimer-, and trimer-anchored graphdiyne (GDY) monolayers. It is shown that most of the TM monomer- and dimer-anchored GDY monolayers have enhanced NRR catalytic activity compared with the Ru(0001) stepped surface. Especially, the Co dimer-anchored GDY monolayer (Co-2@GDY) exhibits the best NRR catalytic activity with the onset potential of -0.43 V and a high ability to suppress the competing hydrogen evolution reaction. The high NRR catalytic activity of Co-2@GDY could be attributed to the localized electronic states near the Fermi level and the strong electron-donating ability of the GDY monolayer. Furthermore, an approximate linear trend between the predicted onset potential and the N adsorption energy is revealed, which may act as a simple descriptor for the intrinsic NRR catalytic activity of such catalysts. Our findings not only propose an efficient and low-cost double-atom catalyst for NRR but also provide a new clue for designing TM atomic catalysts based on GDY sheets for various electrocatalysis applications.