Axially Wired Single‐Site Catalyst Enabled Ampere‐Level Electrocatalytic Ammonia Synthesis From Nitrate

Abstract Electrocatalytic nitrate reduction (NO 3 RR) demonstrates great potential for energy‐efficient ammonia (NH 3 ) synthesis with a low carbon footprint. However, industrial‐level ammonia production is currently limited owing to the insufficient supply of active hydrogen (H * ) from water due to sluggish water‐reductive dissociation at catalytic sites. Inspired by the lysine‐coordinated haem of cytochrome c nitrite reductase, a catalytic architecture is developed through the covalently wiring of iron phthalocyanine (FePc) with carbon nanotubes (CNT) via a pyridine linker. This axially coordinated single‐atom iron catalyst (ACCs‐Fe) achieved an unprecedented NH 3 yield rate of 367.39 mol g cat −1 h −1 and an optimal ammonia Faradaic efficiency (FE) of ≈100%. Through combined in situ spectroscopic characterisation and theoretical calculations, it is demonstrated that the exceptional NO 3 RR performance originated from the pyridine axial coordination‐induced electronic modulation, which simultaneously enhanced water dissociation kinetics (ensuring H * supply) and promoted H * transfer to nitrate/intermediate (enabling deep hydrogenation). This study pioneers the use of axial coordination to accelerate the water‐reductive activation to H * , offering a novel strategy for improving the efficiency of H * ‐mediated NO 3 RR.