A DFT study on benzene adsorption over a corner site of tungsten sulfides

Benzene adsorption on a model for a comer site of a WS(2) slab is considered by periodic DFT calculations. Under typical hydrotreating reaction conditions a fourfold coordination of the comer W atom is thought to be more favorable for benzene adsorption than five- or sixfold coordinated W atoms in conventional edge surfaces. Although no benzene adsorption site was identified on such a comer site, replacement of the W atom adjacent to the W comer site by Ni creates a potential adsorption site around the W corner site. Benzene was found to adsorb with Delta E = -0.19 eV on this Ni-substituted model for the comer site of a WS(2) slab. (C) 2007 Published by Elsevier B.V.