Selective electrochemical nitrogen fixation to ammonia catalyzed by a novel microporous vanadium phosphonate via the distal pathway

Abstract

Herein, a microporous organic–inorganic hybrid, vanadium phosphonate (VPn) material has been developed. With the combined advantages of the periodic organic–inorganic skeleton, a regular microporous channel with a crystalline pore wall, and good surface area, VPn displays electrocatalytic NRR activity with a selective NH₃ yield (11.84 μg h⁻¹ mg_cat⁻¹), faradaic efficiency of 26.29% at −0.6 V and high stability up to 15 h. The isotopic labeling experiment also verifies the electrosynthesis of NH₃ both qualitatively and quantitatively. The theoretical simulation reveals that the associative distal route serves as the most favourable pathway during the NRR, with the first protonation step of *N₂ leading to *NNH as the potential determining step.