Dehydrogenation of Ethanol on a 2Ru/ZrO2(111) Surface: Density Functional Computations

We applied periodic density functional theory to investigate the dehydrogenation of ethanol on a 2Ru/ZrO2 (111) surface. A structure with ethanol adsorbed with its O atom attached to a Ru atom is calculated to exhibit the largest energy of adsorption; it reacts via an O-Ru path: the sequence of bond scission is O-H -> C-beta-H -> C-O that eventually forms ethene and coke. Another structure adsorbed via the alpha-C atom onto Ru that exhibits the second largest adsorption energy dissociates via an C-alpha-Ru path. The sequence of bond scission is C-alpha-H -> O-H -> C-alpha-H ->(C-beta-H ->) C-C, and eventually forms H-2. Possible surfaces of potential energy to form H-2 from a combination of adsorbed H atoms were calculated at the final stage, subject to a barrier about 20-30 kcal/mol, were also calculated. These results indicate that a Ru-doped ZrO2 surface might be a fairly effective catalyst to dehydrogenate ethanol.