| Autor: |
Ferrizz, R. M., Wong, G. S., Egami, T., Vohs, J. M. |
| Zdroj: |
Langmuir; April 2001, Vol. 17 Issue: 8 p2464-2470, 7p |
| Abstrakt: |
Temperature programmed desorption was used to study the reaction of CH3OH on several different ceria-based model catalysts. These catalysts consisted of a CeO2(111) single crystal and thin ceria films supported on α-Al2O3(0001) and yttria-stabilized zirconia (100). The results of this study demonstrate that the reaction of CH3OH on CeO2 surfaces is highly structure sensitive and depends on crystallographic orientation, the concentration of surface oxygen vacancies, and the oxidation state of surface cerium cations. The primary decomposition pathway for methoxide intermediates adsorbed on surface oxygen vacancy sites is dehydrogenation to produce H2CO and surface hydroxyl groups. The surface hydroxyl groups then either react with additional methoxides to reform CH3OH or react to produce H2O. In contrast, methoxides adsorbed on partially reduced ceria surfaces, possibly on Ce3+ sites, undergo complete dehydrogenation to CO and H2. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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