Dissociative adsorption of molecular oxygen on the Cu(001) surface: a density functional theory study
Suleiman, I.A., Radny, M.W., Gladys, M.J., Smith, P.V., Mackie, J.C., Kennedy, E.M. and Dlugogorski, B.Z. (2009) Dissociative adsorption of molecular oxygen on the Cu(001) surface: a density functional theory study. In: Proceedings of the Australian Combustion Symposium, 2 - 4 December, Brisbane, Qld, Australia pp. 103-106.
The presence of atomic oxygen on catalytic surfaces is essential for initiating the oxidation of hydrogen chloride to produce chlorine via the so-called Deacon process. This process provides molecular chlorine for the formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in combustion. In this paper, the dissociative adsorption of molecular oxygen on the Cu(001) surface has been studied using density functional theory. A periodic p(3X2) 4 layer slab was adopted to simulate the adsorption of both molecular and atomic oxygen at a number of adsorption sites. We have found that a bridge-bridge configuration is the most stable structure on Cu(001) with the O₂ molecule adsorbed horizontally. The activation barrier for the dissociative adsorption of O₂ resulting from this configuration was calculated to be 5.1 kcal/mol, with an equivalent transition temperature of ~66 K. This is in good agreement with the experimental value of 40 K obtained under ultra high vacuum conditions. We have also found that a less energetically favourable, vertically oriented, physisorbed structure leads to an almost negligible reaction barrier for the dissociative adsorption of O₂ on Cu(001) (1.5 kcal/mol), with an equivalent transition temperature of ~20 K.
|Publication Type:||Conference Paper|
|Item Control Page|
Downloads per month over past year