Density functional study of chloroethene reactions with iron surfaces

The thermodynamic favorability and resulting structures for chemical adsorption of trichloroethylene (TCE) and tetrachloroethylene (PCE) to iron surfaces were studied using periodic density functional theory (DFT). DFT modeling of adsorbed species was performed using the non-local Perdew-Burke-Enzerhof functional. Chemisorption structures were obtained for the four physically adsorbed initial configurations. Three of the initial configurations placed the plane of the TCE molecule parallel to the Fe [100] surface at bridge, top, and hollow sites. In the fourth initial structure the plane of the TCE molecule was perpendicular to the Fe[100] surface with two Cl atoms at bridge sites between adjacent Fe atoms. TCE and PCE underwent complete dechlorination in one interaction with the iron surface. Trace amounts of mono- and dichloroacetylene may be produced from reactions of TCE and PCE with zerovalent iron. This is an abstract of a paper presented at the 231st ACS National Meeting (Atlanta, GA 3/26-30/2006).