This paper presents a bio-inspired CuCo nanosheet electrocatalyst that mimics the bifunctional nature of copper-type nitrite reductase for efficient nitrate reduction to ammonia. The catalyst achieves a 100 ± 1% Faradaic efficiency at an ampere-level current density of 1035 mA cm⁻² at −0.2 V vs. RHE, with an NH₃ production rate of 4.8 mmol cm⁻² h⁻¹. Mechanistic studies using in situ FTIR and SHINERS spectroscopy reveal a strong synergy between Cu and Co, with Co promoting hydrogenation of NO₃⁻ to NH₃ via adsorbed *H species. The balanced coverage of adsorbed *H and *NO₃ leads to high NH₃ selectivity and yield.
