Interplay between invasive single atom Pt and native oxygen vacancy in rutile TiO₂(110) surface: A theoretical study

Oxygen vacancy (O_v) as well as O_v migration in metal oxide are of great importance in structural evolution of active center in single-atom catalysts (SACs). Here, the interplay between invasive single Pt atom and native O_v in SA-Pt/rutile TiO₂(110) surface, as well as their synergetic effect on water dissociation are investigated by density functional theory (DFT) calculations. We show that importing Pt atom as Pt-ads, Pt_2c, Pt_5c and Pt_6c modes could decelerate the O_v migration effectively, especially in Pt_6c mode. Under oxygen-rich conditions, Pt_6c substitution could make oxygen O_v formation easier, but migration harder. On Pt_6c/Ti_1-yO_2-x1(110) surface, as a bimetal center, Pt_4c-Ti_5c concave could not make water dissociation process easier; however, the O_2c closed to Pt become a good proton acceptor to make water dissociation on Ti_5c-O_2c more convenient with the aid of topmost Ti_5c.