In situ characterization of adsorbed species on methanol synthesis catalysts by FT-IR spectroscopy

Technical Report · Fri Jun 01 04:00:00 EDT 1984

OSTI ID:6859732

Edwards, J F

Transmission infrared spectroscopy was used to characterize adsorbed species on methanol synthesis catalysts during reaction conditions. A copper carbonyl, bidentate formate, and methoxy species were identified as stable surface groups. An adsorbed formaldehyde species was unstable at the reaction temperature, but could be observed on the catalyst surface at the beginning of the reaction. Surface species were very similar for feed mixtures of (1) carbon monoxide and hydrogen, (2) carbon monoxide, carbon dioxide, and hydrogen, and (3) formic acid and hydrogen. The role of copper in methanol synthesis catalysts was to increase the adsorption of carbon monoxide to form a linear carbonyl species. This carbonyl promoted the hydrogenation of formate groups. The formate species was adsorbed on a zinc site (Zn/sub ..beta../) different from the zinc site (Zn/sub ..gamma../) on which formaldehyde and methoxy groups were adsorbed. The rate-determining step in methanol synthesis was determined to be the reaction of hydrogen from a hydroxyl species adsorbed on another zinc site (Zn/sub ..cap alpha../) with a methoxy group to yield methanol. It was established that at the experimental conditions used in this study, the methanol synthesis reaction was far from equilibrium while the water-gas shift reaction was near equilibrium. 186 references, 83 figures, 28 tables.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6859732
• Report Number(s): IS-T-1121; ON: DE84014105
• Country of Publication: United States
• Language: English

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ADSORPTION
ALCOHOLS
ALDEHYDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBOXYLIC ACIDS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
COPPER COMPOUNDS
COPPER OXIDES
DATA
DISPERSIONS
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
FORMALDEHYDE
FORMIC ACID
GASES
HYDROGEN
HYDROXY COMPOUNDS
INFORMATION
INFRARED SPECTRA
KINETICS
METHANOL
MIXTURES
MONOCARBOXYLIC ACIDS
NONMETALS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SHIFT PROCESSES
SORPTION
SORPTIVE PROPERTIES
SPECTRA
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SURFACE PROPERTIES
SYNTHESIS
SYNTHESIS GAS
TRANSITION ELEMENT COMPOUNDS
ZINC COMPOUNDS
ZINC OXIDES