Migration and oxidation of vanadium atom and dimer supported on anatase TiO2(101) surface

The migration and oxidation of single V atom and V2 dimer on the anatase TiO2(1 0 1) surface are systematically studied based on density functional theory (DFT) calculations. For a single V atom, migration on the surface is almost impossible at room temperature while diffusion between surface and subsurface is easy in ultra-high vacuum (UHV) conditon. Without O attraction, single V atom prefers to stay at subsurface interstitial sites. But in oxygen condition, the subsurface interstitial V atom will easily diffuse to the surface and be oxidized into VOn (n = 1-3) monomers. The V2 dimer is dynamically stable on the TiO2(1 0 1) surface and favors to be embedded in the surface layer in UHV condition. However, it can be easily decomposed and oxidized into VOn monomers in the condition of O2. Our results offer an deep insight for the formation mechanism of sublayer vadanium oxides on TiO2 support, and will be instructive for synthesizing desired VOx/TiO2 catalysts.

Automated summary

The migration and oxidation behaviors of a single V atom and V2 dimer on the anatase TiO2(101) surface were systematically studied using DFT calculations. The results reveal that the migration and oxidation of V species vary under different conditions, providing insights for the formation mechanism of sublayer vanadium oxides on TiO2 support.