Spin-induced polarization enables anodic carbon–nitrogen coupling electrocatalysis for sustainable formamide synthesis

Abstract Organic electrosynthesis driven by the renewable electricity and reacted in water offers a green route to prepare higher value-added formamide by constructing carbon–nitrogen (C–N) coupling reactions. Currently, electrochemical formamide synthesis focuses mainly on cathodic processes, required relatively expensive substrates and high electricity and equipment costs, which greatly hinders practical application in industry. Herein, we reported anodic electrosynthesis of formamide from mixed polyols and ammonia by a spin-induced polarization strategy. We proposed that alloying Fe sites into mesoporous CuO broke its long-range antiferromagnetic order and created spin-polarized surface with localized paramagnetic centers. Spin-induced polarization strategy promoted the formation and stabilization of *NH 2 intermediates without overoxidation to unreacted NO 3 − , which behaved as the dominant nucleophile to mediate concerted C–C cleavage and C–N coupling reactions for selective formamide synthesis with minor byproducts at anode. In a flow cell, it delivered a superior formamide Faradaic efficiency of 70.4% and selectivity of 99.0%, with the high net profit of US$1,598 per ton. Meanwhile, the strategy has generally been applied to mixed polyols substrates mimicking the real feedstock from renewable biomass, which further underscored promising industrial application potential. This work establishes a new paradigm to construct efficient C–N coupling reactions for various value-added amides by a spin-state engineering strategy.