在TiO_2(110)表面上H原子形成H_2O的机理研究
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- 英文论文题名：A Study on the Mechanism of H_2O Formation from H atoms on TiO_2(110)
- 论文作者：王锐敏 ; 樊红军
- 英文论文作者：Ruimin Wang ; Hongjun Fan ; Department of Chemistry ; State Key Laboratory of Molecular Reaction Dynamics ; Dalian Institute of Chemical Physics
- 年：2016
- 作者机构：中国科学院大连化学物理研究所分子反应动力学国家重点实验室;
- 论文关键词：TiO_2(110)表面 ; H原子 ; H_2O ; 机理
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十四分会：化学动力学
- 语种：中文
- 分类号：O647
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十四分会 ; 化学动力学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：264k
- 原文格式：D
- 会议级别：全国
摘要
近期,我们采用DFT方法对TiO_2(110)表面上H原子形成H_2O的机理进行了研究。结果显示在TiO_2(110)表面上H原子形成H_2O有两个路径,路径1为两个相邻的桥氧H原子直接形成H_2O并脱附;路径2为两个相邻的桥氧H原子,其中一个H原子首先转移到面氧上,再与另一个桥氧H原子反应生成H_2O并脱附。研究发现这两种路径能垒几乎一样,无论通过哪一种路径,最后H_2O的脱附才是决速步骤。我们分别对以下三种情况进行了理论研究:1)完美的TiO_2(110)表面;2)在两个相邻的桥氧H原子旁有一个氧空位;3)在相对两个相邻的桥氧H原子的另一列桥氧链上有一个氧空位。我们发现情况1中H_2O的脱附能为1.09e V,情况3中H_2O的脱附能为1.10eV,而情况2中H_2O的脱附能为1.47eV,也就是说氧空位与桥氧H原子相对位置是H_2O的脱附能大小的至关影响因素,氧空位离H原子越近H_2O的脱附能越大,氧空位离H原子越远H_2O的脱附能越小。
We calculated the TS barriers for H_2O recombinative desorption from TiO_2(110) surface by DFT method. The two BBO-Hs produce H_2O is endoergic, which we mark this pathway as pathway 1. We take into consideration the other pathway, firstly the H transferred from BBO sites to Os sites, and then the Os–H and BBO-H producing H_2O, it is fortuitously the same with two BBO-H producing H_2O barrier, which we mark this pathway as H_2O pathway 2. In terms of H_2O barriers, in the case of an Ov on the opposite BBO row of H adatoms is the same as the cases of the 1/4 ML H atoms absorbed on the stoichiometric TiO_2(110) surface, we have enough reasons to believe that the relative position of Ov and active H adatoms is having strong effect.
We calculated the TS barriers for H_2O recombinative desorption from TiO_2(110) surface by DFT method. The two BBO-Hs produce H_2O is endoergic, which we mark this pathway as pathway 1. We take into consideration the other pathway, firstly the H transferred from BBO sites to Os sites, and then the Os–H and BBO-H producing H_2O, it is fortuitously the same with two BBO-H producing H_2O barrier, which we mark this pathway as H_2O pathway 2. In terms of H_2O barriers, in the case of an Ov on the opposite BBO row of H adatoms is the same as the cases of the 1/4 ML H atoms absorbed on the stoichiometric TiO_2(110) surface, we have enough reasons to believe that the relative position of Ov and active H adatoms is having strong effect.
引文
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[2]Xu,C.B.;Yang,W.S.;Guo,Q.;Dai,D.X.;Chen,M.D.;Yang,X.M.J.Am.Chem.Soc.2013,135:10206-10209.
[2]Xu,C.B.;Yang,W.S.;Guo,Q.;Dai,D.X.;Chen,M.D.;Yang,X.M.J.Am.Chem.Soc.2013,135:10206-10209.