Sulfur-induced electron redistribution of single molybdenum atoms promotes nitrogen electroreduction to ammonia

Electrochemical nitrogen reduction reaction (NRR) is considered a sustainable approach that endows NH₃ production from N₂ and H₂O under ambient conditions. Due to the sluggish adsorption/activation of N₂ and the strong competition with the hydrogen evolution reaction, advanced NRR electrocatalysts with both high activity and selectivity are required. Herein, we demonstrate a local modulation strategy that simultaneously promotes NRR selectivity and activity on molybdenum-based single atom catalysts (SACs) by sulfur-induced electronic redistribution, delivering a NH₃ yield rate of 46.6 μg·h⁻¹·mg_cat⁻¹ and a Faradaic efficiency of 28.9% at a potential of − 0.2 V vs. RHE in 0.1 M HCl under ambient conditions. This study provides a promising strategy for synergizing the selectivity and activity of electrocatalysts toward multistep NRR. Moreover, such an atomic-level engineering strategy should be applicable to other SACs in general and may have a major impact on their use in electrocatalytic applications.