@article{Li2026, 
author = {Wenying Li and Zeyu Wang and Jun Li and Hai Xiao},
title = {Potential-induced bis-axial coordination in Ir-N-C single-atom catalyst delivers selective C–N coupling for efficient methane amination},
year = {2026},
journal = {Nano Research},
volume = {19},
number = {4},
pages = {94908484},
keywords = {single-atom catalysis, C–N coupling, grand-canonical ensemble density functional theory (GCE-DFT), bis-axial coordination, electrocatalytic methane amination},
url = {https://www.sciopen.com/article/10.26599/NR.2026.94908484},
doi = {10.26599/NR.2026.94908484},
abstract = {Direct electrochemical functionalization of methane remains fundamentally limited by the difficulty of stabilizing reactive CHx 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.}
}