Theoretical Design and Screening of Bimetal-Doped Graphite Nitride Electrocatalysts for Nitrogen Reduction Reaction

Abstract

The electrocatalytic nitrogen reduction reaction (NRR) to achieve ammonia (NH₃) is one of the promising green strategies to fix nitrogen under mild conditions. It is efficient to explore the high activity and selectivity of NRR electrocatalysts by means of the theoretical high-throughput screening integrated with the DFT method. In this work, the dual atom catalysts (DACs) were constructed denoted as MM’@g-C₆N₆ (M/M’ = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Hf, Ta, W), and the electrocatalytic NRR performance of the 120 designed DACs was systematically investigated. Thirteen catalysts with excellent NRR electrocatalytic activities were preliminarily screened out. These were further verified by the calculated Gibbs free energy diagrams and limiting potentials (U_L). The volcano plot between *N adsorption Gibbs free energy (ΔG_*N) and U_L was constructed and could correlate well with the electrocatalytic NRR activities of the screened DACs. In addition, by comparison with U_L values of corresponding hydrogen evolution reaction (HER), 8 electrocatalysts were screened out with excellent NRR activities and selectivities using a 3 + 1 strategy. This study could provide theoretical insights into the NRR electrocatalyst rational design, which might be applicable to sustainable NH₃ production.