An oxygen-coordinated molybdenum single atom catalyst for efficient electrosynthesis of ammonia

Abstract

Electrochemical nitrogen (N₂) reduction has been regarded as a promising strategy for artificial ammonia (NH₃) production under ambient conditions. Herein, we report the fabrication of molybdenum (Mo) single atoms anchored on activated carbon (Mo-SAs/AC) for the electrochemical N₂ reduction to NH₃. The surface-rich oxygen functional groups of activated carbon can effectively capture the Mo precursor, and concurrently act as the coordination sites to anchor Mo single atoms by forming Mo–O_x bonds. As a result, the Mo-SAs/AC as an electrocatalyst shows high activity toward the N₂ reduction reaction (NRR), affording an NH₃ yield rate of 2.55 ± 0.31 mg h⁻¹ mg_Mo⁻¹ and a faradaic efficiency (FE) of 57.54 ± 6.98% at −0.40 V (vs. RHE) in 0.1 M Na₂SO₄ electrolyte with good stability and durability. The constructed Mo–O_x sites are responsible for high NRR activity of Mo-SAs/AC.