Hydrogen Adsorption and Diffusion on the Anatase TiO2(101) Surface: A First-Principles Investigation

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 anat...

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Bibliographic Details
Published in:Journal of physical chemistry. C 2011-04, Vol.115 (14), p.6809-6814
Main Authors: Islam, Mazharul M, Calatayud, Monica, Pacchioni, Gianfranco
Format: Article
Language:English
Subjects:
C: Surfaces, Interfaces, Catalysis
Online Access:Get full text
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Summary: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 H2 molecule. Our calculated activation barrier (E act) shows that migration of H into the bulk is the kinetically most favorable process.
ISSN:1932-7447
1932-7455
DOI:10.1021/jp200408v