Electron-donating N−–Ti3+–Ov interfacial sites with high selectivity for the oxidation of primary C–H bonds

Element doping can fabricate different types of oxygen vacancies (Ov) on TiO2, but the effects of Ov coordination and configuration on the oxidation reaction remain unclear. Here, we modify the local geometric ligand environment of Ov by doping N and B into anatase TiO2 (N-TiO2 and B-TiO2). N−–Ti3+–Ov is induced in N-TiO2 by substituting O with N, which has similar ionic size and electronegativity, and Ti3+–Ov is found in TiO2 and B-TiO2. Density functional theory calculations indicate that N−–Ti3+–Ov is more reactive than Ti3+–Ov toward O2 activation. The resultant N-TiO2-0.25 enriched in N−–Ti3+–Ov contributes to a rapid formation of superoxygen species (•O2−), which increase the oxidation rate of primary C–H bonds in toluene, and thus exhibits much higher selectivity and yield. The fabrication of N−–Ti3+–Ov develops doped catalysts with improved Ov reactivity and enhanced primary C–H bond oxidation selectivity. [Display omitted] •N−–Ti3+–Ov is more reactive than Ti3+–Ov toward O2 activation to generate ⋅O2−•The generation of ⋅O2− is the rate-determining step in selective oxidation of toluene•The introduced photo energy does not change the thermal selective oxidation process•A higher yield of products is attributed to the increased selective oxidation rate Oxygen vacancies in TiO2 influence catalytic activity differently depending on their coordination environment. Chen et al. explore N and B doping and show that N−–Ti3+–Ov is more reactive than Ti3+–Ov toward O2 activation, enhancing the primary C–H bond oxidation of toluene.