Formation of O Adatom Pairs and Charge Transfer upon O-2 Dissociation on Reduced TiO2(110)

Journal Article · Tue Jun 01 04:00:00 EDT 2010 · Physical Chemistry Chemical Physics. PCCP, 12(24):6337-6344

DOI:https://doi.org/10.1039/c000250j· OSTI ID:982547

Du, Yingge; Deskins, N Aaron; Zhang, Zhenrong; Dohnalek, Zdenek; Dupuis, Michel; Lyubinetsky, Igor

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 Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 982547
• Report Number(s): PNNL-SA-70272; 35219; KP1704020
• Journal Information: Physical Chemistry Chemical Physics. PCCP, 12(24):6337-6344, Journal Name: Physical Chemistry Chemical Physics. PCCP, 12(24):6337-6344 Journal Issue: 24 Vol. 12
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATOMS
CONFIGURATION
COULOMB FIELD
DISSOCIATION
ELECTRONS
Environmental Molecular Sciences Laboratory
FUNCTIONALS
OXYGEN
POTENTIAL ENERGY
SCANNING TUNNELING MICROSCOPY
TiO2
O2
STM
DFT
VACANCIES