Industrial-current Ammonia Synthesis by Polarized Cuprous Cyanamide Coupled to Valorization of Glycerol at 4,000 mA cm⁻²

The electrocatalytic nitrate reduction (NO₃RR) holds significance in both NH₃ synthesis and nitrate contamination remediation. However, achieving industrial-scale current and high stability in membrane electrode assembly (MEA) electrolyzer remains challenging due to inherent high full-cell voltage for sluggish NO₃RR and water oxidation. Here, Cu₂NCN with positive surface electrostatic potential V_S(r) is applied as highly efficient NO₃RR electrocatalysts to achieve industrial-current and low-voltage stable NH₃ production in MEA electrolyzer with coupled anodic glycerol oxidation. This paired electro-refinery (PER) system reaches 4000 mA cm⁻² at 2.52 V and remains stable at industrial-level 1000 mA cm⁻² for 100 h with the NH₃ production rate of 97000 µg_NH3 h⁻¹ cm⁻² and a Faradaic efficiency of 83%. Theoretical calculations elucidate that the asymmetric and electron-withdrawing [N−C≡N] units enhance polarization and V_S(r), promoting robust and asymmetric adsorption of NO₃^* on Cu₂NCN to facilitate O−N bond dissociation. A comprehensive techno-economic analysis demonstrates the profitability and commercial viability of this coupled system. Our work opens a new avenue and marks a significant advancement in MEA systems for industrial NH₃ synthesis.