Graphyne-based single atom catalysts for the oxygen reduction reaction: a constant-potential first-principles study

Abstract

Single-atom catalysts (SACs) have recently emerged as promising electrocatalysts for the oxygen reduction reaction (ORR), demonstrating high catalytic efficiency and atom economy. Graphyne (GY), as an exceptionally promising two-dimensional support for SACs, has attracted significant research interest. Herein, the electrocatalytic ORR performance of transition metal-embedded GY systems (M-GY) and their nitrogen-doped counterparts (N-doped M-GY) was investigated by using constant-potential first-principles calculations. Among them, N₀-Co-GY exhibited superior ORR performance both in acidic and alkaline environments. More importantly, our study elucidates the fundamental modification mechanisms by which heteroatom doping configurations modulate the electronic structure and catalytic properties of GY-supported single-atom active sites, providing atomic-level insights into structure–activity relationships. These mechanistic insights offer guidelines for the rational engineering of atomic-scale coordination environments in SACs, particularly for optimizing intermediate adsorption energetics in oxygen electrocatalysis.