Atomically Resolved Studies of Adsorbates on TiO2(110)(Kay's BES/Chemical Physics-Catalysis WBS0502 of Peden's BES-Chemical Transformations at Complex Interfaces, PNNL Scope #47319)
EMSL Project ID
14591
Abstract
The photochemistry of molecules adsorbed on surfaces provides a base of understanding of the photon stimulated process at adsorbate and substrate surface. TiO2 has been intensively investigated as heterogeneous catalysis to destruct the organic compounds in environmental pollutes1. Among the organic compounds, the gas phase methyl halides have been extensively investigated because of their rapid photodissociation2,3. There are several studies about the adsorbed methyl halides4,5, however, there is no structure observation which can be important model system in fundamental studies. This proposal will combine temperature programmed desorption(TPD) and variable temperature scanning tunneling microscopy(VT-STM) to investigate the physical and chemical properties of photo dissociation of methyl halides on TiO2(110). Considering the oxygen vacancies on TiO2 significantly alter the chemical reactivity and electronic structure, experiment will carry on two different TiO2 surfaces, the fully oxidized and reduced.
The experiment will employ a multi-tool surface science ultrahigh vacuum chamber with quadrupole mass spectrometer and an Omicron VT-STM. The preparation of the TiO2(110) surface will be analyzed by low-energy electron diffraction (LEED) and Auger electron spectrometer(AES). The methyl iodide will be dosed to fully oxidized and reduced TiO2(110) surface as a vapor. The CH3I covered surface will be irradiated with a Hg arc lamp.
Reference:
1. Ulrike Diebold， Surf. Sci. Rep. 48(2003), 59
2. Guo, H.; Schatz, G. C. J. Chem. Phys. 93(1990), 393.
3. Johnson, B. R.; Kittrell, C.; Kelly, P. B.; Kinsey, J. L. J. Phys. Chem. 100 (1996), 7743
4. G. Lu, A. Linsebigler and J.T. Yates, Jr. J. Phys. Chem. 99 (1995), 7626
5. S.H. Kim, P.C. Stair and E. Weitz Langmuir 14 (1998), 4156
Project Details
Project type
Exploratory Research
Start Date
2005-05-02
End Date
2007-06-04
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Kim YK, BD Kay, JM White, and Z Dohnalek. 2008. "2-Propanol Dehydration on TiO2(110): The Effect of Bridge-Bonded Oxygen Vacancy Blocking." Surface Science 602(2):511-516. doi:10.1016/j.susc.2007.10.049
Zhang Z, O Bondarchuk, BD Kay, JM White, and Z Dohnalek. 2007. "Direct Visualization of 2-Butanol Adsorption and Dissociation on TiO2(110)." Journal of Physical Chemistry C 111(7):3021-3027. doi:10.1021/jp067461c.
Zhang Z, O Bondarchuk, JM White, BD Kay, and Z Dohnalek. 2006. "Imaging Adsorbate O-H Bond Cleavage: Methanol on TiO2(110)." Journal of the American Chemical Society 128(13):4198-4199.
Zhang Z, RJ Rousseau, J Gong, SC Li, BD Kay, Q Ge, and Z Dohnalek. 2008. "Vacancy Assisted Diffusion of Alkoxy Species on Rutile TiO2(110)." Physical Review Letters 101(15):156103. doi:10.1103/PhysRevLett.101.156103