Cluster and periodic DFT calculations of adsorption of hydroxyl on the Au(h k l) surfaces

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Ana M Pessoa (Author) Other; Jose L C Fajin (Author) FCUP; Jose R B Gomes (Author) Other; Natalia N D S Cordeiro (Author) FCUP

Journal

Title: Journal of Molecular Structure: THEOCHEM

Vol. 946

Pages: 43-50

ISSN: 0166-1280

Publisher: Elsevier B.V.

Indexing

ISI Web of Knowledge - 27 Citations

Scopus - 29 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-003-7CR

DOI: 10.1016/j.theochem.2009.10.024

Abstract (EN): Adsorption of hydroxyl on the Au(1 1 0), Au(1 00). and Au(1 1 1) surfaces has been investigated by means of density functional based methods and cluster models and periodic slabs. According to the cluster models, the optimized results indicate that the use of different functional has an indistinct effect on the equilibrium geometry, but adsorption energies computed by different exchange-correlation functionals may differ up to 0.8 eV. At the B3LYP level, the final structures of adsorbed OH are upright and the preferred modes for its adsorption onto the Au(1 1 0), Au(1 00), and Au(1 1 1) surfaces are the short-bridge site with an adsorption energy of -1.96 eV, the bridge site (-1.79 eV), and the hollow hcp site (-1.25 eV), respectively. According to the periodic calculations, the final (OH)(ads) Structures are in a few cases more tilted as compared to the cluster model data, as well as giving a different preferred adsorption site for the Au(1 1 1) surface (i.e.: the bridge site). Furthermore, the stability order of adsorption gathered on the three surfaces, i.e.: Au(1 1 0) > Au(1 0 0) > Au(1 11), is in accord with experimental reports and in concordance with the decreasing of the coordination number of the gold atoms in each surface. Finally, periodic calculations carried out for the stepped Au(3 2 1) surface reveal that adsorption of OH is more favorable on the bridge between the Au(1 1 1) and Au(1 0 0) microfacets, and its adsorption energy is higher than on the low-index surfaces.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8