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

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 grandcanonical ensemble density functional theory(GCE-DFT),we reveal how an applied anodic potential induces evolution of the axial coordination environment on a graphene-supported IrN_(4)single-atom catalyst to enable selective methane amination.Constant-potential GCE-DFT calculations show that IrN_(4)evolves into a bis-axial*CH_(2)-*NH_(2)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*CH_(2)carbene.Electronic structure analyses identify minimized Pauli repulsion and cooperativeσ-πinteractions as the key factors governing this preferential axial coordination.Kinetic analyses further demonstrate that*CH_(2)in this bis-axial*CH_(2)-*NH_(2)motif acts as a chemoselective electrophile that delivers low-barrier,concerted C-N coupling with solution-phase NH_(3),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.