Temperature-programmed reaction/desorption and reflection-absorption infrared spectroscopy have been employed to investigate the thermal reactions and adsorption geometry of FCH2CH2OH molecules on clean and oxygen-preadsorbed Cu(100) surfaces. Molecular desorption predominates in heating FCH2CH2OH adsorbed on clean Cu(100). However, ∼20% adsorbed FCH2CH2OH molecules at about half-monolayer coverage dissociate on the surface to form water, ethylene, and 1,4-dioxane. On the other hand, monolayer FCH2CH2OH completely dissociates on oxidized Cu(100) to form 1,4-dioxane and the surface intermediate of FCH2CH2O(g), which further decomposes to evolve FCH2CHO(g) at temperatures higher than ∼350 K. The decomposition of FCH2CH2OH to form FCH2CH2O(g) on oxidized Cu(100) begins at ∼ 160 K and is completed by 220 K. On clean Cu(100), FCH2CH 2OH molecules at ∼0.25 monolayer coverage are adsorbed with the C-C-O skeleton approximately parallel to the surface. The C-C-O skeleton tilts away from the surface as the exposure is increased to a half-monolayer coverage. However, the parallel C-C-O orientation is not observed on the oxidized surface, even at the FCH2CH2OH exposure for a 0.25 monolayer coverage.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry