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.