Communication—Electrochemical Reduction of N <sub>2</sub> to Ammonia by Vanadium Oxide Thin Films at Neutral pH: Oxophilicity and the NRR Reaction
Ashwin Ganesan, Adaeze Osonkie, Precious Chukwunenye, Ishika Rashed, Thomas R. Cundari, Francis D’Souza, Jeffry A. Kelber
Abstract
Electroreduction of N 2 to NH 3 is an energy- and environmentally-friendly alternative to the Haber-Bosch process. Little is known, however, about reactive sites for electrochemical nitrogen reduction reaction (NRR) at Earth-abundant oxide or oxynitride surfaces. Here, we report N-free V III/IV -oxide films, created by O 2 plasma oxidation of polycrystalline vanadium, exhibiting N 2 reduction at neutral pH with an onset potential of −0.16 V vs Ag/AgCl. DFT calculations indicate that N 2 scission from O-supported V-centers is energetically favorable by ∼18 kcal mol −1 compared to N-supported sites. Theory and experiment yield fundamental insights concerning the effect of metal oxophilicity towards design of earth-abundant NRR electrocatalysts.