Zeolite-mediated hybrid Cu+/Cu0 interface for electrochemical nitrate reduction to ammonia

The electrocatalytic conversion of reactive nitrogen species to ammonia is a promising strategy for efficient NH3 synthesis. In this study, we reveal that the hybrid Cu+/Cu0 interface is catalytically active for electrochemical ammonia synthesis from nitrate reduction. To maintain the hybrid Cu+/Cu0 state at negative reaction potentials, hydrophilic zeolite is used to modify Cu/Cu2O electrocatalyst, which demonstrates an impressive NH3 production rate of 41.65 mg h−1 cm−2 with ∼100% Faradaic efficiency of ammonia synthesis at −0.6 V vs. RHE. In-situ Raman spectroscopy unveil the high activity originates from the zeolite reconstruction at the electrode–electrolyte interface, which protects the valence state of Cu0/Cu+ site under negative potential and promotes electrochemical activity towards NH3 synthesis.