Electrochemical N2 fixation to NH3 under ambient conditions: Mo2N nanorod as a highly efficient and selective catalyst

Abstract

A highly attractive, but still a key challenge, is the development of earth-abundant electrocatalysts for efficient NH₃ electrosynthesis via the N₂ reduction reaction (NRR). In this communication, we report the development of a Mo₂N nanorod as a highly efficient and selective NRR electrocatalyst for artificial N₂ fixation in acidic electrolytes under ambient conditions. In 0.1 M HCl, this catalyst achieved a high Faradaic efficiency of 4.5% with a NH₃ yield of 78.4 μg h⁻¹ mg_cat.⁻¹ at −0.3 V vs. a reversible hydrogen electrode, thus outperforming most reported NRR electrocatalysts under ambient conditions and some under harsh conditions. Density functional theory calculations revealed that the free energy barrier of the potential determining step of NRR on MoO₂ decreases dramatically after nitrogenization.