CO Oxidation Mechanism on Tungsten Nanoparticle

Abstract

CO oxidations on the surface of tungsten nanoparticle W₁₀ and on W(111) surface were investigated by density functional theory (DFT) calculations. The molecular structures and surface–adsorbate interaction energies of CO and O₂ on the W₁₀ and W(111) surfaces were predicted. Three CO oxidation reactions of CO + O₂ → CO₂ + O, CO + O + O → CO₂ + O, and CO + O → CO₂ were considered in Eley–Rideal (ER) and Langmuir–Hinshelwood (LH) reaction mechanisms. The nudged elastic band (NEB) method was applied to locate transition states and minimum energy pathways (MEP) of CO oxidation on the W₁₀ and W(111) surfaces. All reaction barriers were predicted, implying the CO oxidations on both the W₁₀ nanoparticle and W(111) surfaces prefer the ER mechanism. The electronic density of states (DOS) was calculated to understand the interaction between adsorbates and surfaces for the CO oxidation process. In this study, we have demonstrated that the catalytic ability of W₁₀ nanoparticles is superior to that of the W(111) surface for CO oxidation