The mechanism of higher oxygenate synthesis over supported Rh catalysts
- Univ. of Akron, OH (United States)
Extensive mechanistic studies have shown that higher oxygenates are formed from the insertion of CO into adsorbed alkyl species that is generated from CO dissociation and partial hydrogenation. The reduced Rh surface is known to be responsible for the formation of alkyl species. However, little is known about the nature of the active sites for CO insertion on various promoted Rh catalysts that are active for higher oxygenate synthesis. In situ infrared spectroscopy reveals linear CO on the single reduced Rh site as the most active adsorbed CO species for CO insertion on Rh/SiO{sub 2} and Cu-, Ag-, Ce, and Mn-promoted Rh/SiO{sub 2} catalysts. Tilted CO exhibiting a band below 1700 cm{sup -1} is identified as a spectator that does not participate in CO insertion. Increasing reaction pressure causes an increase in the residence time of alkyl intermediate allowing CO insertion to occur. The selectivity toward higher oxygenates can be improved by increasing the relative concentration of linear CO sites and by increasing reaction pressure.
- OSTI ID:
- 254725
- Report Number(s):
- CONF-940813--
- Country of Publication:
- United States
- Language:
- English
Similar Records
The selective pathway to higher oxygenates from CO, H{sub 2}, olefins and chlorocarbons
The synthesis of higher oxygenates from CO related reactions