Electron-donating N−–Ti3+–Ov interfacial sites with high selectivity for the oxidation of primary C–H bonds
Cheng Chen, Wu Mingge, Chenggong Yang, Xiaolin Yu, Jing Yu, Haibo Yin, Ganggang Li, Guijin Su, Zhengping Hao, Maoyong Song, Chunyan Ma
Abstract
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.