Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, October 1, 1996--December 30, 1996
A series of MgO-based Cu catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. The bulk composition of the catalyst has been measured by atomic absorption (AA) analysis and the Cu dispersion has been determined by N{sub 2}O titration at 363 K. Kinetic studies of ethanol coupling reactions on Cu{sub 0.5}Mg{sub 5}CeO{sub x} and 1.0 wt % K-Cu{sub 0.5}Mg{sub 5}CeO{sub x} catalyst indicates that at similar steady-state acetaldehyde concentrations, the presence of K increases the rates of base-catalyzed aldol coupling reactions to acetone and butyraldehyde. Aldol coupling chain growth reaction rates on 1.2 wt % K-Cu{sub 7.5}Mg{sub 5}CeO{sub x} are higher than on 1.0 wt % K-Cu{sub 0.5}Mg{sub 5}CeO{sub x} even though basic site densities are similar on both samples, suggesting that Cu metal sites are also involved in rate-determining steps required for condensation reactions. Cu appears to enhance the desorption of H{sub 2} via the migration of H species from basic to Cu sites and makes the basic sites available for subsequent C-H bond activation steps. Addition of CO{sub 2} decreases the rate of base-catalyzed chain growth reaction to acetone, but does not affect the rate of ethanol dehydrogenation reaction on Cu metal sites
- Research Organization:
- Lawrence Berkeley Lab., CA (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
- DOE Contract Number:
- AC22-94PC94066
- OSTI ID:
- 589252
- Report Number(s):
- DOE/PC/94066--T9; ON: DE98004748
- Country of Publication:
- United States
- Language:
- English
Similar Records
Carbon-carbon bond formation pathways in CO hydrogenation to higher alcohols
Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 April--30 June 30 1996