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

Abstract

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.