The effects of titania overlayers on C2H4/CO/H2 reactions over a Rh foil |
| |
| Authors: | K. J. Williams A. B. Boffa M. Salmeron A. T. Bell G. A. Somorjai |
| |
| Affiliation: | (1) Center for Advanced Materials, Lawrence Berkeley Laboratory Departments of Chemistry, University of California, 94720-9989 California, Berkeley, USA;(2) Center for Advanced Materials, Lawrence Berkeley Laboratory Departments of Chemical Engineering, University of California, 94720-9989 Berkeley, California, USA |
| |
| Abstract: | The effects of submonolayer deposits of titania on the activity and selectivity of a Rh foil catalyst for C2H4/CO/H2 reactions have been investigated. Reactions were carried out at 1 atm total pressure and at temperature of 488 K and 523 K. The addition of titania to the catalyst enhances the total rate of C3-oxygenate formation. This rate enhancement is due entirely to an increase in the rate of 1-propanol formation, which reaches a maximum at a TiOx. coverage of 0.2 ML. The rate of propanal formation, by contrast, is not enhanced. The rates of formation of methane, ethane, and C3-hydrocarbons also exhibit rate maxima at a TiOx. coverage of 0.2 ML. The rates of formation of C4- and C5-hydrocarbons, on the other hand, are suppressed by titania addition. The higher rate of 1-propanol production in the presence of titania is attributed to an interaction between Ti3+ ions at the edge of TiOx. islands and the carbonyl bond of adsorbed C3-oxygenated species. Such interactions are envisioned to facilitate hydrogenation of the carbonyl bond. |
| |
| Keywords: | Titania-rhodium catalysts model oxide-metal catalysts hydroformylation over Rh-TiO2 combined ethylene and CO hydrogenation over Rh-TiO2 |
| 本文献已被 SpringerLink 等数据库收录！ |
|
