First-Principles Theoretical Study and Scanning Tunneling Microscopic Observation of Dehydration Process of Formic Acid on a TiO2(110) Surface†
First-Principles Theoretical Study and Scanning Tunneling Microscopic Observation of Dehydration Process of Formic Acid on a TiO2(110) Surface†
复制标题
DOI：
10.1021/jp0497460
复制
发表时间：
2004-06
影响因子：
3.3
通讯作者：
Y. Morikawa;Ittetsu Takahashi;Masaki Aizawa;Y. Namai;Takehiko Sasaki;Y. Iwasawa
中科院分区：
文献类型：
--
作者：
Y. Morikawa;Ittetsu Takahashi;Masaki Aizawa;Y. Namai;Takehiko Sasaki;Y. Iwasawa
采用第一性原理理论计算研究了甲酸在TiO_2（110）表面上的脱水过程。甲酸解离吸附形成甲酸根和羟基。事实证明，甲酸盐在化学计量表面上的简单分解过程在能量上是不利的。两个相邻的桥连羟基形成H2O和O空位相对容易，活化能垒计算为114 kJ/mol。在具有氧缺陷位的TiO 2（110）表面上，甲酸盐与一个O吸附在缺陷位处，与另一个O吸附在五重Ti上，形成桥接配置。甲酸盐的进一步分解通过具有129 kJ/mol的活化势垒的单齿构型发生。我们还进行了相应的STM观测的理论结果。结果表明，在高温下，一些甲酸盐沿着氧排分布在氧排和钛排之间的中间位置。
We have studied the dehydration process of formic acid on a TiO2(110) surface by using first-principles theoretical calculations. Formic acid dissociatively adsorbs to form formate and hydroxyl. It turns out that simple decomposition processes of the formate on the stoichiometric surface are energetically unfavorable. The formation of H2O and O vacancies from two neighboring bridging hydroxyls is relatively easy and the activation barrier is calculated to be 114 kJ/mol. On the TiO2(110) surface with oxygen defect sites, formate adsorbs with one O at a defect site and with the other O on a five-fold Ti, forming a bridging configuration. Further decomposition of the formate occurs through a monodentate configuration with an activation barrier of 129 kJ/mol. We have also performed STM observation corresponding to the theoretical results. It was imaged that some formates were located along the oxygen row and at an intermediate position between the oxygen row and the Ti row at elevated temperatures at which re...