Theoretical screening of a graphyne-supported transition metal single-atom catalyst for the N₂ reduction reaction

The electrocatalytic nitrogen reduction reaction (NRR) is a promising technology for the synthesis of NH₃ in an ambient environment. However, developing low-cost and high-efficiency electrocatalysts still remains a long-standing challenge. In this work, density function theory (DFT) calculations are done to systematically investigate the NRR catalytic activity of transition metals (TM = Sc-Cu, Y-Ag, and Hf-Au) supported on monolayer graphyne (GY). TM@GY (TM = Sc, V, Mn, Y, Tc, and Os) with excellent NRR performance are demonstrated. The mixed pathway is the most favorable for Sc, V, Y, and Os@GY with the potentials of -0.37, -0.27, -0.40, and -0.36 V, respectively, while the distal reaction pathway is most favorable for Mn and Tc@GY with the potentials of -0.37 and -0.42 V. Most strikingly, Mn, Tc, and Os@GY exhibit high NRR selectivity. This work provides a screening scheme for exploring highly efficient electrocatalysts for the electrochemical NRR under ambient conditions.