Microenvironment-Directed Product Selectivity in Electrochemical C–N Coupling: Recent Advancements and Future Outlook

The C–N bond is integral to essential agronomical, biochemical, and industrial products, including urea, amides, amines, amino acids, oximes, and pharmaceuticals. Whereas traditional synthesis demands costly noble metals, extreme temperatures, and high pressures that generate toxic pollution, electrocatalytic C–N coupling provides a highly selective, green alternative powered by renewable electricity under ambient conditions. By co-reducing abundant feedstocks like CO2, CO, N2, and NOx, this method tackles the profound thermodynamic barriers of breaking robust N≡N and C=O bonds. Nevertheless, the simultaneous reduction of carbon and nitrogen introduces severe kinetic hurdles, notably mismatched intermediate reaction rates and aggressive competing side reactions. Overcoming these barriers requires highly stable catalysts operating at low potentials, coupled with rigorous microenvironment engineering adapted from mature CO2 and NOx/N2 reduction systems. By precisely shaping mass transport, reactant coverage, and local electric fields, selectivity is maximized through three primary strategies: targeted catalyst design utilizing defect engineering, ligand coordination, and nanoscale morphological control across single-atom, single-metal, and bimetallic architectures; dynamic pulsed electrolysis; and electrolyte tuning via pH and cation modifications. By comprehensively evaluating these catalytic innovations, substrate activation mechanisms, characterization techniques, and integrated electrolytic cell configurations, this review provides a definitive roadmap for translating laboratory-scale organonitrogen electrosynthesis into sustainable, large-scale industrial manufacturing through microenvironment tuning.