Self-Optimization With Oriented Facet Reconstruction for Universal Electrocatalytic C-N Coupling

Electrocatalytic C-N coupling represents a green synthesis platform, yet the dynamic evolution of catalyst surfaces during the reaction remains poorly understood. Here, we report a nitrate-dominated, preferential facet evolution on Cu single crystals that directs less active (110) and (100) facets toward the highly active (111) configuration. The Cu(111) surface delivers a urea yield of 5.2 mg h^-1 cm^-2 from CO₂ and NO₃ ^-, outperforming (110) and (100) by about 4- and 26-fold, respectively, while maintaining excellent stability. Experimental and theoretical analyses reveal that this facet reconstruction is associated with spontaneous chemical interaction between nitrate and metallic copper, alongside the thermodynamic stability of the Cu(111) facet. Significantly, the pristine Cu(111) surface consistently outperforms Cu(110) and Cu(100), highlighting its intrinsic catalytic superiority. This work provides insights into nitrate-dominated C-N coupling, advancing the design of dynamically active electrocatalysts.