Thermal Decomposition of Bulk K-CoMoSx Mixed Alcohol Catalyst Precursors and Effects on Catalyst Morphology and Performance

Journal Article · Wed Sep 26 00:00:00 EDT 2012 · Applied Catalysis A: General

DOI:https://doi.org/10.1016/j.apcata.2012.06.010· OSTI ID:1047923

Menart, Martin J.; Hensley, Jesse E.; Costelow, Kellen E.

Cobalt molybdenum sulfide-type mixed alcohol catalysts were synthesized via calcination of precipitated bulk sulfides and studied with temperature programmed decomposition analysis. Precursors containing aqueous potassium were also considered. Precipitates thermally decomposed in unique events which released ammonia, carbon dioxide, and sulfur. Higher temperature treatments led to more crystalline and less active catalysts in general with ethanol productivity falling from 203 to 97 g (kg cat){sup -1} h{sup -1} when the calcination temperature was increased from 375 to 500 C. The addition of potassium to the precursor led to materials with crystalline potassium sulfides and good catalytic performance. In general, less potassium was required to promote alcohol selectivity when added before calcination. At calcination temperatures above 350 C, segregated cobalt sulfides were observed, suggesting that thermally decomposed sulfide precursors may contain a mixture of molybdenum and cobalt sulfides instead of a dispersed CoMoS type of material. When dimethyl disulfide was fed to the precursor during calcination, crystalline cobalt sulfides were not detected, suggesting an important role of free sulfur during decomposition.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Bioenergy Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1047923
• Report Number(s): NREL/JA-5100-55666; TRN: US201216%%556
• Journal Information: Applied Catalysis A: General, Vol. 437-438, Issue 26 September 2012
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
AMMONIA
CALCINATION
CARBON DIOXIDE
CATALYSTS
COBALT
COBALT SULFIDES
DISULFIDES
ETHANOL
MIXTURES
MOLYBDENUM
MORPHOLOGY
PERFORMANCE
POTASSIUM
POTASSIUM SULFIDES
PRECURSOR
PRODUCTIVITY
PYROLYSIS
SULFIDES
SULFUR
temperature programmed decomposition
mixed alcohols
bulk metal sulfide
potassium promoter