Hydrogen Adsorption and Diffusion on the Anatase TiO2(101) Surface: A First-Principles Investigation
Hydrogen Adsorption and Diffusion on the Anatase TiO2(101) Surface: A First-Principles Investigation
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DOI：
10.1021/jp200408v
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发表时间：
2011-04-14
影响因子：
3.7
通讯作者：
Pacchioni, Gianfranco
中科院分区：
文献类型：
--
作者：
Islam, Mazharul M.;Calatayud, Monica;Pacchioni, Gianfranco
本文用密度泛函理论（DFT）研究了氢在金红石型TiO_2（101）表面的吸附和扩散机制，并与氢在金红石型TiO_2（110）表面的扩散机制进行了比较。由于金红石和金红石表面的氧环境不同，在金红石表面上的H结合能比在金红石中小0.2- 0.3eV。H扩散的各种过程进行了研究，使用攀登轻推弹性带（cNEB）的方法。我们已经确定了三个主要的扩散机制，导致迁移的H在表面上，扩散到体，和解吸的H-2分子。我们计算的活化势垒（E-act）表明，迁移到散装的H是动力学上最有利的过程。
The mechanisms of adsorption of hydrogen on the anatase TiO2(101) surface and of its diffusion in the bulk are investigated with DFT calculations and compared with similar results obtained for the diffusion of hydrogen on the rutile (110) surface. Because of the different oxygen environments in anatase and rutile surfaces, the H binding energy on the anatase surface is 0.2-0.3 eV smaller than in rutile. Various processes for H diffusion are investigated using the climbing nudged-elastic-band (cNEB) approach. We have identified three main diffusion mechanisms, leading to migration of H on the surface, diffusion into the bulk, and desorption of H-2 molecule. Our calculated activation barrier (E-act) shows that migration of H into the bulk is the kinetically most favorable process.