Trifunctional catalysts for conversion of syngas to alcohols. Seventh quarterly report, March 1-May 31, 1986. [CO chemisorbed on Rh/Al/sub 2/O/sub 3/]

Technical Report · Mon Jun 09 04:00:00 EDT 1986

OSTI ID:5619445

Emphasis was placed on structure characterization of catalysts previously prepared and tested for activity and selectivity for hydrogenation of CO. Two series of Rh/Al/sub 2/O/sub 3/ catalysts were examined - those modified by addition of Na or by addition of Mo. Examination of Rh/Na/Al/sub 2/O/sub 3/ catalysts by transmission electron microscopy confirms the size of Rh particles, about 70 Angstrom units, and EDAX measurements, the presence of Al, Rh, and Na when applicable. Infrared measurements of CO chemisorbed on Rh/Al/sub 2/O/sub 3/ show linear and bridged complexes. With addition of Na, the C - O stretching frequency decreases, implying a stronger C - Rh bonding. The implications of this on the catalytic activity and selectivity are discussed. Temperature programmed reduction (TPR) measurements show broad peaks consistent with well-dispersed Rh. The amount of hydrogen uptake indicates the reduction of Rh from 3 + TO 0, within the accuracy of the test. Further work will be reported later. In regard to Rh/Mo/Al/sub 2/O/sub 3/ catalysts , a more detailed examination of the products distribution shows that the percentage C2 oxygenates stays the same as for Rh/Al/sub 2/O/sub 3/, even though the activity of the catalyst has increased ten fold. The C1 oxygenates have been greatly increased, at the expense of decreased CH/sub 4/. This implies that CH/sub 4/ and CH/sub 3/OH come from the same intermediate. The energy of activation was estimated to be 22,000 cal per mole for both Rh/Al/sub 2/O/sub 3/ and Rh/Mo/Al/sub 2/O/sub 3/. This leads to the important conclusion that the increased activity of Mo modified catalysts is not due to a lowering of the activation energy but to more efficient site utilization, possibly by more effective activation of hydrogen by Mo. 6 figs., 1 tab.

• Research Organization: Delaware Univ., Newark (USA). Center for Catalytic Science and Technology
• DOE Contract Number: FG22-84PC70780
• OSTI ID: 5619445
• Report Number(s): DOE/PC/70780-T4; ON: DE86011486
• Country of Publication: United States
• Language: English

Related Subjects

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10 SYNTHETIC FUELS
ALCOHOLS
ALKALI METALS
ALKANES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
DATA
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
EXPERIMENTAL DATA
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROGENATION
HYDROXY COMPOUNDS
INFORMATION
INFRARED SPECTRA
MEDIUM PRESSURE
METALS
METHANE
METHANOL
MICROSCOPY
MOLYBDENUM
NONDESTRUCTIVE ANALYSIS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
REDUCTION
RESEARCH PROGRAMS
RHODIUM
SCATTERING
SEPARATION PROCESSES
SODIUM
SORPTION
SPECIFICITY
SPECTRA
SYNTHESIS
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY EMISSION ANALYSIS
X-RAY FLUORESCENCE ANALYSIS
YIELDS