CO Oxidation Mechanism on Tungsten Nanoparticle

CO oxidations on the surface of tungsten nanoparticle W-10 and on W(111) surface were investigated by density functional theory (DFT) calculations. The molecular structures and surface-adsorbate interaction energies of CO and O-2 on the W-10 and W(111) surfaces were predicted. Three CO oxidation reactions of CO + O-2 -> 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 W-10 and W(111) surfaces. All reaction barriers were predicted, implying the CO oxidations on both the W-10 nanoparticle and W(111) surfaces prefer the ER mechanism. The electronic density of states (DOS) was calculated to understand the interaction adsorbates and surfaces for the CO oxidation process. In this study, we have demonstrated that the catalytic ability of W-10 nanoparticles is superior to that of the W(111) surface for CO oxidation.