The adsorption and dissociation of O-2 molecules on W(111) surface with different coverage have been studied at the density functional theory (DFT) level in conjunction with the projector augmented wave (PAW) method. The molecular structures and surface-adsorbent interaction energies of W(111)/O and W(111)/O-2 systems are predicted. In these studies, four adsorption sites, such as top (T), bridge (B), shallow (S), and deep (D) sites, of the W(111) surface are considered. The calculated results show that the O-2 molecule on the W(111) surface can exist in the both end-on and side-on adsorption mode. For the end-on adsorption mode, it was found that the favorable adsorption configuration of W(111)/O-2 is at top (T) site with an adsorption energy of -44.3 kcal/mol. For the side-on adsorption mode, O-2 molecule also prefers to adsorb at the top (T) site. The adsorption energy is calculated to be -63.8 kcal/mol. The nudged elastic band (NEB) method is applied to locate transition states and minimum energy pathways (MEP). It is found that a little dissociation barrier exists in the system of O-2 molecule adsorbed on W(111) surface.
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JOURNAL OF COMPUTATIONAL AND THEORETICAL NANOSCIENCE Volume: 8 Issue: 12 Special Issue: SI Pages: 2434-2438
