Low-Temperature Electrocatalytic Ammonia Production: Study on the Nitrogen-Reducing Activity of Vanadium Sulfide Catalysts

High Resolution Image Download MS PowerPoint Slide Several transition metal dichalcogenides (TMDs) that are active for electrochemical nitrogen reduction (e-NRR) remain underexplored, particularly regarding the correlation between their surface electronic states and e-NRR activity. For example, π-backdonation supposedly occurs in the associative e-NRR at the V 2+ active sites in vanadium sulfides (VS x ); but the hypothesis was not experimentally validated with the reaction-oriented surfaces remained under debate (V 2+ vs V 4+ ). To resolve these issues, we synthesized several metal sulfides, including VS x specimens with controlled oxidation states and studied the effects of electronic structure modulation on the e-NRR activity. The incorporation of Cu into VS x resulted in enhanced e-NRR activity (131.24 μg mg cat –1 h –1 or 0.62 mA cm geo –2 in 0.5 M Na 2 SO 4, pH7), primarily owing t…