Journal article
The adhesion and shape of nanosized Au particles in a Au/TiO2 catalyst
Departament de Quimica Fisica, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona, Spain1
Center for Atomic-scale Materials Physics, CAMP, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark2
Haldor Topsøe A/S, Nymøllevej 55, DK-2800 Lyngby, Denmark3
The adhesion, shape, and electronic structure of gold particles supported on TiO2(110) have been determined by density-functional theory calculations, to gain more insight into the catalytic activity of small supported gold particles. These calculations show that gold particles do not bind to a perfect TiO2 surface, but have a binding energy of about 1.6 eV/defect on an oxygen vacancy in TiO2.
This results in an indirect effect of the support material on the catalytic activity: The distribution and dynamics of the oxygen vacancies determine the dispersion and shape of the gold particles, which in turn affect the catalytic activity. A theoretical analysis of the gold particle shape reveals that it is flat, about 3–4 layers for a gold particle of 3 nm diameter.
The calculated flat geometry is in good agreement with electron microscopy and EXAFS measurements of a high surface area Au/TiO2 catalyst containing 2.4 wt% gold.
| Language: | English |
|---|---|
| Year: | 2004 |
| Pages: | 86-94 |
| ISSN: | 10902694 and 00219517 |
| Types: | Journal article |
| DOI: | 10.1016/j.jcat.2004.03.036 |
