Two-dimensional metal–organic framework Mo3(C2O)12 as a promising single-atom catalyst for selective nitrogen-to-ammonia conversion

Abstract

The development of single-atom catalysts (SACs) for the electrocatalytic nitrogen reduction reaction (NRR) remains a great challenge. Using density functional theory calculations, we design a new family of two-dimensional metal–organic frameworks [TM₃(C₂O)₁₂, TM = Sc–Au] and explore their feasibility as SACs for the NRR. The calculated adsorption Gibbs free energies of N₂ and NNH species demonstrate that only the Mo₃(C₂O)₁₂ monolayer could both activate the NN bond and stabilize the adsorbed NNH intermediate. The Mo₃(C₂O)₁₂ metal–organic framework not only possesses sufficient stability, but also exhibits high nitrogen fixation activity and substantial selectivity. The NRR distal pathway could achieve this sufficient goal with a low limiting potential of −0.36 V and a promising theoretical faradaic efficiency value of 100%. This work could give guidance to develop more effective NRR SACs using 2D metal–organic frameworks under ambient conditions.