Formation of O Adatom Pairs and Charge Transfer upon O-2 Dissociation on Reduced TiO2(110)
Scanning tunneling microscopy and density functional theory have been used to investigate the details of O2 dissociation leading to the formation of oxygen adatom (Oa) pairs at terminal Ti sites. An intermediate, metastable Oa-Oa configuration with two nearest-neighbor O atoms is observed after O2 dissociation at 300 K. The nearest-neighbor Oa pairs are destabilized by Coulomb repulsion of charged Oa’s that separate further along the Ti row into energetically more favorable second-nearest neighbor configuration. The potential energy profile calculated for O2 dissociation on Ti rows and following Oa’s separation strongly supports the experimental observations. Furthermore, our results suggest that the itinerant electrons associated with the O vacancies are being utilized in the O2 dissociation process at the Ti row, whereas at least two oxygen vacancies per O2 molecule are required in order for this process to become viable.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 982547
- Report Number(s):
- PNNL-SA-70272; 35219; KP1704020; TRN: US201014%%373
- Journal Information:
- Physical Chemistry Chemical Physics. PCCP, 12(24):6337-6344, Vol. 12, Issue 24
- Country of Publication:
- United States
- Language:
- English
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