Theoretical study of ethyl alcohol adsorbed on a germanium (100) surface

The chemical reaction of ethyl alcohol on a germanium surface was investigated through density functional theory analysis. The most stable product containing the HO-Ge-Ge-CH₂CH₃ linkage was formed via OC-dissociative adsorption. Kinetic studies revealed that the OH-dissociative reaction pathways have relatively low activation barriers and may, respectively, occur at room temperature. Configurationally, the oxygen atom of the ethoxy fragment was bonded to the germanium atom, and the ethyl group was oriented either perpendicular or parallel to the germanium surface. The two configurations had similar adsorption energies and activation barriers. Further reaction of the dissociated hydrogen with a nearby electron-rich germanium atom passivated the dangling bond. Theoretical scanning tunneling microscopy images simulated based on the OH-dissociative adsorption revealed a better agreement with the experimentally observed adsorption features than those of other possible structures.