Electrocatalytic reduction of nitrite to ammonia on undercoordinated Cu.

Electrocatalytic NO 2 - -to-NH 3 reduction (NO 2 RR) has emerged as an intriguing route for simultaneous mitigation of harmful nitrites and production of valuable NH 3 . Herein, we design for the first time undercoordinated Cu nanowires (u-Cu) as an efficient and selective NO 2 RR electrocatalyst, delivering the maximum NO 2 - -to-NH 3 faradaic efficiency of 94.7% and an ammonia production rate of 494.5 μmol h -1 cm -2 at -0.7 V vs. RHE. Theoretical calculations reveal that the created undercoordinated Cu sites on u-Cu can enhance NO 2 - adsorption, boost NO 2 - -to-NH 3 energetics and restrict competitive hydrogen evolution, thereby enabling the active and selective NO 2 RR.