Efficient Heteronuclear Diatom Electrocatalyst for Nitrogen Reduction Reaction: Pd–Nb Diatom Supported on Black Phosphorus

Electrocatalytic N₂ reduction reaction (eNRR) is a promising alternative to the traditional Haber–Bosch method for large-scale ammonia production because of its low pollution and low energy consumption. By means of density functional theory (DFT) calculations, a thermodynamically stable Pd–Nb heteronuclear diatom catalyst supported on 2D black phosphorus (PdNb@BP) is designed, which is predicted to exhibit excellent catalytic activity toward eNRR with an ultralow overpotential (0.20 V) and a small NH₃ desorption free energy (0.17 eV), by combining the advantages of Nb atoms for N₂ activation and of Pd atoms for NH₃ desorption, and a high eNRR selectivity over the competing hydrogen evolution reaction. It is highlighted that the participation of one additional N₂ molecule in the mechanism is important for the catalyst to realize the catalytic process.