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Diffusion and Photon-Stimulated Desorption of CO on TiO2(110)
- Source :
- The Journal of Physical Chemistry C. 122:15382-15389
- Publication Year :
- 2018
- Publisher :
- American Chemical Society (ACS), 2018.
-
Abstract
- Thermal diffusion of CO adsorbed on rutile TiO2(110) was studied in the 20–110 K range using photon-stimulated desorption (PSD), temperature-programmed desorption (TPD), and scanning tunneling microscopy. During UV irradiation, CO desorbs from certain photoactive sites (e.g., oxygen vacancies). This phenomenon was exploited to study CO thermal diffusion in three steps: first, empty these sites during a first irradiation cycle, then replenish them with CO during annealing, and finally probe the active site occupancy in the second PSD cycle. The PSD and TPD experiments show that the CO diffusion rate correlates with the CO adsorption energy—stronger binding corresponds to slower diffusion. Increasing the CO coverage from 0.06 to 0.44 monolayer (ML) or hydroxylation of the surface decreases the CO binding and increases the CO diffusion rate. Relative to the reduced surface, the CO adsorption energy increases and the diffusion decreases on the oxidized surface. The CO diffusion kinetics can be modeled satisfa...
- Subjects :
- Materials science
Annealing (metallurgy)
Kinetics
Analytical chemistry
chemistry.chemical_element
02 engineering and technology
010402 general chemistry
021001 nanoscience & nanotechnology
01 natural sciences
Oxygen
0104 chemical sciences
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
law.invention
General Energy
Adsorption
chemistry
law
Desorption
Monolayer
Irradiation
Physical and Theoretical Chemistry
Scanning tunneling microscope
0210 nano-technology
Subjects
Details
- ISSN :
- 19327455 and 19327447
- Volume :
- 122
- Database :
- OpenAIRE
- Journal :
- The Journal of Physical Chemistry C
- Accession number :
- edsair.doi...........a649afc823d07071b59cbcd3b9789f7c