Potential-induced bis-axial coordination in Ir-N-C single-atom catalyst delivers selective C–N coupling for efficient methane amination

Direct electrochemical functionalization of methane remains fundamentally limited by the difficulty of stabilizing reactive CH_x intermediates while suppressing overoxidation and competing side reactions. Using grand-canonical ensemble density functional theory (GCE-DFT), we reveal how an applied anodic potential induces evolution of the axial coordination environment on a graphene-supported IrN₄ single-atom catalyst to enable selective methane amination. Constant-potential GCE-DFT calculations show that IrN₄ evolves into a bis-axial *CH₂–*NH₂ resting state that dominates over a broad potential–pH window. This potential-induced configuration offers dual advantages: It excludes oxygenated ligands to suppress the oxygen evolution reaction and stabilizes a reactive, electrophilic surface *CH₂ carbene. Electronic structure analyses identify minimized Pauli repulsion and cooperative σ–π interactions as the key factors governing this preferential axial coordination. Kinetic analyses further demonstrate that *CH₂ in this bis-axial *CH₂–*NH₂ motif acts as a chemoselective electrophile that delivers low-barrier, concerted C–N coupling with solution-phase NH₃, outperforming competing C–C and C–O coupling pathways. These findings establish potential-induced axial coordination as a powerful design principle for directing single-atom catalysis and provide a mechanistic foundation for selective methane-to-amine conversion.