Ab-initio pseudopotential study of electronic structure and chemisorption of oxygen on aluminium surface

Chemisorption of oxygen atom on aluminium (111), (110) and (10 0) surfaces is studied using ab-initio plane wave pseudopotential method based on density functional theory (DFT). Oxygen atom chemisorbed on three different high symmetry sites; top, short-bridge and hollow sites on the aluminium surfaces are examined. It has been found that the O-adatom adsorbed at the hollow site on aluminium (1111), (110) and (10 0) plane yield energetically most stable structure. Calculation of chemisorption energies of O-adatom on aluminium. surfaces shows that oxygen is most strongly bound to aluminium atoms on Al(111) plane and the calculated value of the chemisorption energy of O-adatom at the hollow site on Al(111) surface is 4.8 eV. In this work, the chemisorption energies calculated for O-adatom on Al(110) and Al(100) surfaces are reported for the first time. The electronic structures and the electronic charge density distributions of the oxygen chemisorbed aluminium surfaces are also investigated. Calculations show that for aluminium, p orbitals also contribute significantly along with the s orbitals during the bond formation with oxygen atom. Therefore, the possibilities of hybridizations lead to the strong bonding configurations. (C) 2008 Elsevier Ltd. All rights reserved.