摘要
通过程序升温脱附谱的方法探究了266nm激光照射下异丙醇在锐钛矿TiO2（101）表面的光化学，并提出了详细的解离机理．在光照作用下，异丙醇发生分步解离：首先，O-H键断裂生成异丙氧基；然后，仲碳的C-H键在光照的作用下进一步发生解离，从而生成丙酮，两步生成的氢原子均转移到相邻的桥氧上．在升温过程中，这部分氢原子会与分子态的异丙醇发生置换反应，从而以低温水和高温异丙基的形式从表面脱附出来．
Photocatalysis of 2-propanol on A-TiO2（101） has been investigated using a temperature programed desorption method with 266 nm laser light. A clear mechanism is proposed for photodissociation of 2-propanol on A-TiO2（101）. Acetone product on five coordinate Ti4＋ sites is formed in a stepwise manner in which the O-H dissociation proceeds first and then followed by secondary C-H dissociation of 2-propanol while H atoms are transferred to the adjacent bridge bond oxygen （BBO） sites. Low temperature water is formed in a thermally driven process via H-atom on BBO in exchange with isopropyl groups of molecule 2-propanol, while isopropyl radical desorbs at high temperature during the TPD process. The observation demonstrates the prospect of TiO2 as a photocatalyst for degradation of organics.
作者
耿振华
陈晓
郭庆
戴东旭
杨学明
Zhen-hua Genga b Xiao Chena(a. State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Dalian 115023, China b. University of Chinese Academy of Sciences, BeLiinE 100049, China)
基金
This work was supported by the Chinese Academy of Sciences, the National Natural Science Foundation of China （No.21403224）, the Chinese Ministry of Science and Technology （No.2013CB834605）, the Youth Innovation Promotion Association CAS, and the Key Research Program of the Chinese Academy of Sciences.
