Forging Sustainable Carbon–Nitrogen Bonds from CO₂ and NO_x: Mechanistic Insights and Catalyst Design for Electrochemical C-N Coupling

Electrochemical C-N coupling between carbon sources (CO₂, CO) and nitrogen feedstocks (NO_x) offers a sustainable route to synthesize value-added organonitrogen compounds under ambient conditions. This strategy circumvents the high-temperature and multistep limitations of thermochemical processes while simultaneously mitigating carbon and nitrogen pollution. Despite recent advances, the reaction suffers from slow kinetics, competing side reactions, and limited selectivity. This review highlights mechanistic insights and catalyst design principles that govern efficient C-N bond formation. We discuss reaction pathways from CO₂/CO and NO_x precursors, identifying key intermediates (^*COOH, ^*CO, ^*NO, ^*NH₂) through operando spectroscopy and theory. Catalyst architectures, including dual-atom sites, heterostructure interfaces, vacancy-engineered lattices, and single-atom frameworks, modulate local charge distribution to favor selective coupling. At the system level, advances in reactor configuration and electrolyte optimization further enhance efficiency and stability. Finally, emerging directions in multimodal diagnostics, machine learning-driven catalyst discovery, and technoeconomic evaluation outline a roadmap for scalable electrochemical C-N coupling. Together, these efforts establish a foundation for sustainable nitrogen chemistry and renewable-powered carbon utilization.