SO_x Oxidation Kinetics on Pt(111) and Pd(111): First-Principles Computations Meet Microkinetic Modeling

This work examines the complex nature of SO_x (x = 0–4) interaction and oxidation on Pt(111) and Pd(111) surfaces using density functional theory (DFT) calculations coupled with microkinetic modeling. Thermodynamic and kinetic analyses suggest similar adsorption and oxidation behaviors for SO_x species on both metal surfaces, although the observed greater tendency of Pd to undergo sulfating is borne out by the present results. Selected quantities computed using DFT, when used in a previously developed microkinetic model, are shown to predict SO₂ conversion as a function of temperature in excellent agreement with available experimental data.