Adsorption geometry of CO versus coverage on TiO2(110) from s- and p-polarized infrared spectroscopy
The adsorption of CO on reduced, rutile TiO2(110) is investigated using IR reflection-absorption spectroscopy and temperature programmed desorption. Experiments using s- and p-polarized IR light incident along the [001] and ]011[ azimuths give detailed information on the adsorption geometry of the CO as a function of the CO coverage, θCO. The results indicate that for 0 < θCO ≤ 1 ML, CO adsorbs oriented normal to the surface at Ti5c sites. For 1 < θCO ≤ 1.5 ML, the bonding geometry of the CO adsorbed at Ti5c sites is unchanged, while the additional CO molecules adsorb at OB sites parallel to the surface and parallel to the ]011[ azimuth. The results do not support previous suggestions that CO at Ti5c sites tilt ~20° from normal to reduce repulsive interactions at high coverages. The results demonstrate the utility of polarization-resolved infrared reflection-adsorption spectroscopy for elucidating adsorption geometries on dielectric substrates.
- 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:
- 1064585
- Report Number(s):
- PNNL-SA-90608; 46005; KC0301020
- Journal Information:
- Journal of Physical Chemistry Letters, 3(23):3425-3430, Journal Name: Journal of Physical Chemistry Letters, 3(23):3425-3430
- Country of Publication:
- United States
- Language:
- English
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