SO_<i>x</i> Oxidation Kinetics on Pt(111) and Pd(111): First-Principles Computations Meet Microkinetic Modeling

Abstract

This work examines the complex nature of SO_<i>x</i> (<i>x</i> = 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_<i>x</i> 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