Re-examining the role of subsurface oxygen vacancies in the dissociation of H2O molecules on anatase TiO2

Aldehyde Hydrogenation by Pt/TiO2 Catalyst in Aqueous Phase: Synergistic Effect of Oxygen Vacancy and Solvent Water

“…In some experiments, with H 2 pretreatment at the relatively high temperature, some Pt clusters could be fully encapsuled by thin TiO 2−x layers, leading to the strong metal−support interaction (SMSI). 73−75 Yet, due to the easy hydrolysis of surface Ov in water, 76,77 this encapsulation is hard to take place in aqueous phase at the mild temperature, which is not taken into account in the simulations, and the details are discussed in the Supporting Information. For charge analysis, the Bader charges are calculated from the code 78,79 First of all, several ab initio molecular dynamics (AIMD) simulations are performed to compare how the Pt clusters evolve over the stoichiometric TiO 2 and reduced TiO 2−x support in both gas phase as a reference and aqueous phase.…”

“…For the reduced TiO 2 surface, an oxygen vacancy (Ov) is formed by removing one bridge oxygen (O br ), which corresponds to ∼10% surface O br atoms and is close to the amount of several percent in experiments. , Previous studies have already shown that the metal clusters will favorably bind on the Ov site, , so the pyramid-like Pt 14 cluster is initially placed over Ov, which model is denoted Pt/TiO 2– x in Figure S1b. In some experiments, with H 2 pretreatment at the relatively high temperature, some Pt clusters could be fully encapsuled by thin TiO 2– x layers, leading to the strong metal–support interaction (SMSI). − Yet, due to the easy hydrolysis of surface Ov in water, , this encapsulation is hard to take place in aqueous phase at the mild temperature, which is not taken into account in the simulations, and the details are discussed in the Supporting Information. For charge analysis, the Bader charges are calculated from the code , by Henkelman et al based on the density file of valence electrons.…”