Adsorption and dissociation of water on LaB6(100) investigated by surface vibrational spectroscopy
| Autor: | Yuan Ren, Yukihiro Moriya, Thomas Yorisaki, Chuhei Oshima, Shigeki Otani, Michael Trenary, Aashani Tillekaratne |
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| Rok vydání: | 2012 |
| Předmět: |
Analytical chemistry
High resolution electron energy loss spectroscopy Infrared spectroscopy Surfaces and Interfaces Lanthanum hexaboride Condensed Matter Physics Surfaces Coatings and Films Amorphous solid chemistry.chemical_compound Adsorption chemistry Chemisorption Materials Chemistry Absorption (chemistry) Self-ionization of water |
| Zdroj: | Surface Science. 606:247-252 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/j.susc.2011.09.025 |
| Popis: | The chemisorption of water (H 2 O and D 2 O) on a LaB 6 (100) surface was studied with reflection absorption infrared spectroscopy (RAIRS) and high resolution electron energy loss spectroscopy (HREELS). The clean surface was exposed to H 2 O and D 2 O at temperatures from 90 K to room temperature, and spectra were acquired after heating to temperatures as high as 1200 K. It was found that water molecularly adsorbs on the surface at 90 K as a monomer at low coverages and as amorphous solid water at higher coverages. Water adsorbs dissociatively at room temperature to produce surface hydroxyl species as indicated by OH/OD stretch peaks at 3676/2701 cm −1 . Room temperature adsorption also reveals low frequency loss features in HREEL spectra near 300 cm −1 that are quite similar to results obtained following the dissociative adsorption of O 2 . In the latter case, the loss features were attributed to the La O stretch of O atoms bridge-bonded between two La atoms. In the case of dissociative adsorption of H 2 O, the low frequency loss features could be due to either the La O vibrations of adsorbed O or of adsorbed OH. |
| Databáze: | OpenAIRE |
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