Adsorption of Ar Atoms on the Relaxed and Defect-Free TiO2(110) Surface

J. R. B. Gomes(a), J. P. Prates Ramalho(b)

(b)Departamento de Química,Universidade de Évora, R. Romão Ramalho, 59, 7000 Évora, Portugal; [email protected]

Rutile titanium dioxide is an important material with a wide range of applications in several areas of material and surface science such as catalysis, photocatalysis and microelectronics [1,2]. Recently, this material gained even more attention due to the extraordinarily high activity for low temperature catalytic combustion, partial oxidation of hydrocarbons, hydrogenation of unsaturated hydrocarbons and reduction of nitrogen oxides catalyzed by ultrafine gold particles dispersed on TiO2 [2]. Argon adsorption plays a crucial role on probing the surface topography of oxide surfaces and for the adsorption on rutile surfaces there are vast amounts of reliable experimental data available.
In this poster presentation it will be reported a detailed theoretical study concerning the relaxation of a TiO2(110) surface and the adsorption of Argon atoms on several different sites of this relaxed oxide surface. The calculations were carried out on a periodic slab (12 or 15 layers, 1x1 or 2x2 cells) in the framework of Density Functional Theory using the GGA-based Perdew-Wang (PW91) exchange-correlation functional [3] as implemented in the VASP 4.4.2 code [4]. The projector augmented wave (PAW) potentials [5] have been used to describe the core and expand the electron density of all atoms. For the plane wave set a cutoff energy of 415 eV was used and the Brillouin-zone integrations have been performed using 4 × 4 × 3 up to 10 × 10 × 6 Monkhorst-Pack grids depending on the size of the unit cell. Further, a vacuum width of 10 ? was used throughout all calculations. Recently, the computational strategy presented above was found to yield very good results for other complex oxides such as Al2O3 and Fe2O3(0001) surfaces [6].

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