Single Molybdenum Atom Anchored on N‑Doped Carbon as a Promising Electrocatalyst for Nitrogen Reduction into Ammonia at Ambient Conditions

Ammonia (NH₃) is one of the most important industrial chemicals owing to its wide applications in various fields. However, the synthesis of NH₃ at ambient conditions remains a coveted goal for chemists. In this work, we study the potential of the newly synthesized single-atom catalysts, i.e., single metal atoms (Cu, Pd, Pt, and Mo) supported on N-doped carbon for N₂ reduction reaction (NRR) by employing first-principles calculations. It is found that Mo₁-N₁C₂ can catalyze NRR through the enzymatic mechanism with an ultralow overpotential of 0.24 V. Most importantly, the removal of the produced NH₃ is rapid with a free-energy uphill of only 0.47 eV for the Mo₁-N₁C₂ catalyst, which is much lower than that for ever-reported catalysts with low overpotentials and endows Mo₁-N₁C₂ with excellent durability. The coordination effect on activity is further evaluated, showing that the experimentally realized active site, single Mo atom coordinated by one N atom and two C atoms (Mo-N₁C₂), possesses the highest catalytic performance. Our study offers new opportunities for advancing electrochemical conversion of N₂ into NH₃ at ambient conditions.