Electron-donating N--Ti3+-Ov interfacial sites with high selectivity for the oxidation of primary C-H bonds
Electron-donating N--Ti3+-Ov interfacial sites with high selectivity for the oxidation of primary C-H bonds
复制标题
DOI：
10.1016/j.xcrp.2022.100936
复制
发表时间：
2022-07-20
影响因子：
8.9
通讯作者：
Ma, Chunyan
中科院分区：
文献类型：
--
作者：
Chen, Cheng;Wu, Mingge;Ma, Chunyan
元素掺杂可以在TiO 2表面形成不同类型的氧空位（O-v），但O-v配位和构型对氧化反应的影响尚不清楚。在这里，我们通过将N和B掺杂到TiO_2（N-TiO_2和B-TiO_2）中来修改Ov的局部几何配体环境。N-TiO_2中的N-Ti ~（3+）-Ov是由离子尺寸和电负性相似的N取代O而产生的，TiO_2和B-TiO_2中均存在Ti ~（3+）-Ov。密度泛函理论计算表明，N-Ti ~（3+）-Ov比Ti ~（3+）-Ov对O ~-2的活化反应更活跃。所得的N-TiO_2 -0.25富含N-Ti_（3+）-O_v，有助于快速形成超氧物种（dO_（2）（-）），提高了甲苯中初级C-H键的氧化速率，从而显示出高得多的选择性和产率。N-Ti ~（3+）-Ov的制备开发了具有改进的Ov反应性和增强的初级C-H键氧化选择性的掺杂催化剂。
Element doping can fabricate different types of oxygen vacancies (O-v) on TiO2, but the effects of O-v 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 electronega-tivity, 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 O-2 activation. The resultant N-TiO2-0.25 enriched in N--Ti3+-Ov contributes to a rapid formation of superoxygen spe-cies (dO(2)(-)), 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.