Boosting the Electrocatalytic Nitrogen Reduction Reaction Activity on Two-Dimensional Conductive Metal–Organic Frameworks: A Theoretical Study

Electrocatalytic nitrogen reduction reaction (NRR) is a promising alternative to the traditional Haber-Bosch process to generate ammonia (NH₃). Exploring NRR electrocatalysts with efficient performance and stability is crucial for NH₃ production. In this work, on the basis of density functional theory (DFT) calculations, we systematically studied various TMO₄-HTP and TMN₄-HTP (TM refers to V, Cr, Mn, Fe, Co, Ni, Nb, Mo, Ru, Rh, Pd, Ta, W, Re, Os, Ir, and Pt; HTP refers to hexatriphenylene) of conductive two-dimensional (2D) metal-organic frameworks (MOFs) as potential electrocatalysts for the NRR. The strong interaction between TM atoms and the O₄-HTP/N₄-HTP substrates could guarantee the thermodynamic and electrochemical stabilities of the designed TMO₄-HTP and TMN₄-HTP. The calculated results suggest that ReO₄-HTP, MoO₄-HTP, and MoN₄-HTP could serve as promising electrocatalysts. Moreover, ReO₄-HTP possesses the highest activity with a calculated limiting potential value of -0.34 V. Notably, ReO₄-HTP exhibits good NRR selectivity with the effective suppression of the hydrogen evolution reaction (HER). Our results contribute to searching for NRR electrocatalysts and highlight a potentially efficient class of catalysts based on 2D MOF materials for electrochemical reactions.