DFT研究羟基氧化金红石型TiO <sub>2</sub>（110）表面上一氧化氮与氨和水的反应机理,The Journal of Physical Chemistry C

当前位置： X-MOL 学术 › J. Phys. Chem. C › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

DFT研究羟基氧化金红石型TiO ₂（110）表面上一氧化氮与氨和水的反应机理
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2017-07-25 00:00:00 , DOI: 10.1021/acs.jpcc.7b04811
Xiao-Ying Xie ₁ , Qian Wang ₁ , Wei-Hai Fang ₁ , Ganglong Cui ₁

Affiliation

一氧化氮（NO）是重要的空气污染物。最近，其化学转化为氨（NH ₃）和水（H ₂ O）分子引起了许多实验关注。在这项工作中，我们采用了周期性密度泛函理论方法并结合平板模型来研究NO吸附在羟基化金红石型TiO ₂（110）表面的催化反应。我们获得了两个有利的NO吸附结构：在第一个中，末端N原子与Ti _{5 c}表面原子（N _ad O）结合；在第二个原子中，N和O原子都与两个附近的Ti _5c表面原子（N _ad O _ad）键合。有趣的是，N随着羟基覆盖率的增加，_ad O _ad变得比N _ad O更稳定，即在我们的平板模型中三个以上的羟基覆盖，这表明羟基可以严重影响表面电子结构，从而影响表面催化。从机理上讲，我们发现N-O键在解离之前应先被弱化。在N _ad O吸附结构中，这种弱化是通过将氢原子转移到NO分子的N原子来实现的。在N _ad O _ad中吸附结构，该N–O键在被表面吸附时已经被激活。N–O键断裂后，一系列氢原子转移至N或O原子，最终产生最终产物。我们目前的计算结果为从TiO ₂表面去除NO提供了重要的机械原理。

"点击查看英文标题和摘要"

DFT Study on Reaction Mechanism of Nitric Oxide to Ammonia and Water on a Hydroxylated Rutile TiO2(110) Surface

Nitric oxide (NO) is an important air pollutant. Its chemical conversion to ammonia (NH₃) and water (H₂O) molecules has recently attracted a lot of experimental attention. In this work, we have employed a periodic density functional theory method combined with a slab model to study the catalytic reaction of NO adsorbed on a hydroxylated rutile TiO₂(110) surface. We have obtained two favorable NO adsorption structures: in the first one, the terminal N atom is bonded with a Ti_5c surface atom (N_adO); in the second one, both the N and O atoms are bonded with two nearby Ti_5c surface atoms (N_adO_ad). Interestingly, N_adO_ad becomes more stable than N_adO with the increasing coverage of hydroxyl groups, i.e., more than three hydroxyl groups in our slab model, which demonstrates that hydroxyls can seriously influence surface electronic structures and, thus, surface catalysis. Mechanistically, we have found that the N–O bond should be weakened prior to its dissociation. In the N_adO adsorption structure, this weakening is achieved through a hydrogen atom transfer to the N atom of the NO molecule; in the N_adO_ad adsorption structure, this N–O bond is already activated upon adsorption on the surface. After the N–O bond is broken, a series of hydrogen atom transfers to either the N or O atom take place, which eventually produces the final products. Our present computational results provide important mechanistic insights into NO removal from TiO₂ surfaces.

更新日期：2017-07-26

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南

全部期刊列表>>