Methane Dissociative Adsorption on the Pt(111) Surface over the 300−500 K Temperature and 1−10 Torr Pressure Ranges
| Autor: | Kevin A. Becraft, Anderson L. Marsh, Gabor A. Somorjai |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Auger electron spectroscopy
Sum-frequency generation Hydrogen Infrared spectroscopy chemistry.chemical_element Photochemistry Dissociation (chemistry) Methane Surfaces Coatings and Films chemistry.chemical_compound Adsorption chemistry Torr Materials Chemistry Physical chemistry Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Physical Chemistry B. 109:13619-13622 |
| ISSN: | 1520-5207 1520-6106 |
| Popis: | The dissociative adsorption of methane on the Pt(111) surface has been investigated and characterized over the 1−10 Torr pressure and 300−500 K temperature ranges using sum frequency generation (SFG) vibrational spectroscopy and Auger electron spectroscopy (AES). At a reaction temperature of 300 K and a pressure of 1 Torr, C−H bond dissociation occurs in methane on the Pt(111) surface to produce adsorbed methyl (CH3) groups, carbon, and hydrogen. SFG results suggest that C−C coupling occurs at higher reaction temperatures and pressures. At 400 K, methyl groups react with adsorbed C to form ethylidyne (C2H3), which dehydrogenates at 500 K to form ethynyl (C2H) and methylidyne (CH) species, as shown by SFG. By 600 K, all of the ethylidyne has reacted to form the dissociation products ethynyl and methylidyne. Calculated C−H bond dissociation probabilities for methane, determined by carbon deposition measured by AES, are in the 10-8 range and increase with increasing reaction temperature. A mechanism has been... |
| Databáze: | OpenAIRE |
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