Direct Observation of Site Specific Molecular Chemisorption of O2 on TiO2 (110)

Journal Article · Thu Dec 16 04:00:00 EST 2010 · The Journal of Physical Chemistry Letters, 1(24):3524-3529

DOI:https://doi.org/10.1021/jz101535f· OSTI ID:1004820

Wang, Zhitao; Du, Yingge; Dohnalek, Zdenek; Lyubinetsky, Igor

Molecularly chemisorbed O2 species were directly imaged on reduced TiO2(110) at 50 K with high-resolution scanning tunneling microscopy (STM). Two different O2 adsorption channels, one at bridging oxygen vacancies (VO) and another at five-fold coordinated terminal titanium atoms (Ti5c), have been identified. While O2 species at Ti5c site appears as a single protrusion centered on the Ti5c row, the O2 at VO manifests itself by a disappearance of the VO feature. It is found that STM tip can easily dissociate O2 species, unless extremely low magnitudes of the tunneling parameters are used. The O2 molecules chemisorbed at low temperatures at these two distinct sites are the most likely precursors for the two previously established O2 dissociation channels, observed at temperatures above 150 and 230 K at the VO and Ti5c sites, respectively.

• 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: 1004820
• Report Number(s): PNNL-SA-76519; 35219; KP1704020
• Journal Information: The Journal of Physical Chemistry Letters, 1(24):3524-3529, Journal Name: The Journal of Physical Chemistry Letters, 1(24):3524-3529 Journal Issue: 24 Vol. 1
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ADSORPTION
ATOMS
CHEMISORPTION
DISSOCIATION
Environmental Molecular Sciences Laboratory
O2
OXYGEN
SCANNING TUNNELING MICROSCOPY
STM
TITANIUM
TUNNELING
TiO2
VACANCIES
adsorption