| AVS 55th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS+NC-MoA |
| Session: | Reactivity at Oxide Surfaces |
| Presenter: | H. Idriss, University of Auckland, New Zealand |
| Authors: | H. Qiu, Ruhr-University Bochum, Germany Y. Wang, Ruhr-University Bochum, Germany P. McGill, University of Auckland, New Zealand H. Idriss, University of Auckland, New Zealand C. Woell, Ruhr-University Bochum, Germany |
| Correspondent: | Click to Email |
The reaction of CH2O with perfect and defective TiO2(110) surfaces (produced by over-annealing and Ar ion sputtering methods) was studied by thermal desorption spectroscopy (TDS), high resolution electron energy loss spectroscopy (HREELS) and DFT calculations. Exposing the perfect TiO2(110) surface to CH2O at 100 K leads to the formation of physisorbed CH2O and paraformaldehyde. The latter decomposes to CH2O that desorbs at about 270 K. On the defective TiO2(110) surface CH2O adsorbs more strongly on oxygen vacancy sites ultimately forming a diolate (-OCH2CH2O-) species, as demonstrated by HREELS. Upon heating to higher temperatures this species undergoes deoxygenation resulting in ethylene formation via a reductive coupling mechanism.