Methanol adsorption and decomposition on image surface: A density functional theory study

The adsorption and subsequent dissociative reaction of methanol (CH3OH) on clean image surface were investigated using the density functional theory methods and the periodic slab models. There are three adsorption modes of methanol were investigated. Among the two initially-stable adsorbed CH3OH structures, the pathways of methanol dissociation via bond scission of the Osingle bondH, Csingle bondH and Csingle bondO bonds to form methoxide, hydroxymethyl and methyl radicals, respectively, were examined. Several possible pathways for CH3OH decomposition on the image surface were proposed. Our calculated results pointed out that the most favorable reaction pathway is CH3OH(a) → CH3O(a) + H(a) → CH2O(a) + 2H(a) → CH2O(g) + 2H(a). In addition, the nature of the surface–methanol bonding was investigated through scrutiny of electron density difference (EDD) contour plot.