resumo
Adsorption of several ionic and non-ionic species (OH-, O, O-, O2-, H, H+ and H-) on the low-index Miller Au (hkl) surfaces has been investigated by means of density functional theory based methods. The stability order for adsorptions on the three surfaces decreases with the increasing of the coordination number of the outermost gold atoms in each surface, i.e., Au(110)>Au(100)>Au(111), which is in agreement with the experimental evidences. The detailed COOPs analysis of the various adsorption sites for all adsorbates in the surface with the most stable adsorption(s), Au(110), evidenced that adsorption in the gold surfaces may be a function of particle size and charge and substantiates the variability in the order of preferences sites for the adsorption of the different species found in these low-index Miller Au( hkl) surfaces. This variability increases with the increasing of the stability of the adsorptions on the gold surfaces, i.e., the Au(110) presents more variability in the order of preferences sites for the adsorption of different species. (C) 2011 Elsevier B.V. All rights reserved.
palavras-chave
EFFECTIVE CORE POTENTIALS; SINGLE-CRYSTAL ELECTRODES; DENSITY-FUNCTIONAL THEORY; TOTAL-ENERGY CALCULATIONS; AUGMENTED-WAVE METHOD; GOLD ELECTRODES; ELECTROCATALYTIC OXIDATION; ELECTROCHEMICAL OXIDATION; MOLECULAR CALCULATIONS; CHARGE-DISTRIBUTION
categoria
Chemistry; Physics
autores
Pessoa, AM; Fajin, JLC; Gomes, JRB; Cordeiro, MNDS
nossos autores
José R. B. Gomes
Investigador Principalagradecimentos
Thanks are due to Fundacao para a Ciencia e Tecnologia (FCT), Lisbon, Portugal and to FEDER for financial support to REQUIMTE and to CICECO. Programme Ciencia 2007 is also acknowledged. JLCF acknowledges FCT for the grant SFRH/BPD/64566/2009 co-financed by the Fundo Social Europeu (FSE).