| AVS 54th International Symposium | |
| Surface Science | Wednesday Sessions |
| Session SS1-WeM |
| Session: | Oxide Surface Reactivity |
| Presenter: | S.-C. Li, University of Texas at Austin |
| Authors: | S.-C. Li, University of Texas at Austin J.M. White, University of Texas at Austin Z. Zhang, Pacific Northwest National Laboratory B.D. Kay, Pacific Northwest National Laboratory Z. Dohnálek, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
The TiO2 chemistry has been widely investigated in both fundamental science and technical applications, due to its intriguing chemical properties. One of the important applications is the photochemical hydrogen production from H2O. On a prototypical TiO2(110) surface, the bridge-bonded oxygen (BBO) vacancies have been shown to be the primary reactive sites for H2O dissociation yielding geminate pairs of OH groups. In this study we use variable temperature Scanning Tunneling Microscopy (STM) to investigate intrinsic hydrogen diffusion along the BBO rows as a function of temperature. The hopping rates deduced from the consecutively collected STM images at temperatures ranging from 320K to 420K are analyzed. The prefactors and activation barriers are extracted as a function of OH-OH separation using the Arrhenius analysis. A comparison of the hopping rates for hydrogen and deuterium shows a strong isotope effect.
The research described in this presentation was performed in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.