Atomic Nb Anchoring on Graphdiyne as a New Potential Electrocatalyst for Nitrogen Fixation: A Computational View

The exploration of effective active catalysts for the synthesis of ammonia NH3 is of vital importance to the development of the industrial dinitrogen-fixation industry. Herein, a series of single transition metal atoms is screened anchoring on a monolayer graphdiyne (TM@GD, TM = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Nb, Mo, Ru, Rh, Pd, Ag, W, Ir, Pt, and Au) toward electrocatalytic N-2 reduction reaction nitrogen reductive reaction (NRR) by density functional theory (DFT) calculations. Several TM@GD, including Ti@GD, V@GD, Nb@GD, Ru@GD, and W@GD, are computed to experience relatively lower free energy uphill for NRR than Ru(0001) surface. Specifically, the Nb@GD is demonstrated to be the most excellent for NRR with a limited potential of only 0.27 V, and also a high selectivity of 49.95% in spite of hydrogen evolution reaction (HER) competition simply estimated by Boltzmann distribution. Distal pathway is identified here without the formation of N2N4 species, ensuring a highly oriented product of NH3. Studies in this work would facilitate further experimental research in this field with a new idea and guidance to find out the active catalysts of high efficiency for NH3 synthesis at room temperature.