Density Functional Theory Study on the Structure and Catalytic Activity of Sulfur-Doped Iron-Based Single-Atom Catalysts
The impact of sulfur(S)atoms doping on the structural stability and catalytic activity of iron-based single-atom catalysts was investigated using density functional theory calculations.Structural optimization and free energy calculations were employed to assess the thermodynamic and electrochemical stability of the S-doped configurations.The results demonstrated that S atoms adopted a satellite-like arrangement surrounding the active sites of the single-atom catalyst,leading to a stable catalyst structure and modulation of the electronic structure of the active sites.Furthermore,a comparison was made between the catalytic activities of the pristine catalyst and the S-doped catalysts,revealing a significant reduction in the overpotential of the oxygen reduction reaction upon S doping,particularly in systems with broken symmetry.