Cation promotion effect in zeolite-supported F-T catalysts: Final report
The present work was undertaken to investigate systematically the influence of Group IA neutralizing cations on CO hydrogenation over zeolite-supported ruthenium catalysts. These catalysts were prepared from NH/sub 4/Y, LiY, NaY, KY, RbY, CsY, NaX, KL, and Na-mordenite zeolites by ion exchange with ruthenium hexammine chloride. The nature of the group IA cations was found to have little effect on chemisorptive properties and on the activity and chain growth probability in CO hydrogenation on Ru. However, it was established that secondary acid-catalyzed reactions of the primary olefinic products from CO hydrogenation can play a major role in shaping product selectivity. Using model reactions such as olefin transformations on the zeolites without the metal, it was established that the strength of the acid sites is a strong function of the nature of the neutralizing alkali cations remaining in the zeolite. Acid site strength was found to decrease with molecular weight of the alkali cation used. This study established the bifunctional nature of the zeolite-supported F-T catalysts and its importance in CO hydrogenation. The results suggest that the catalyst selectivity can be controlled by varying the strength of the zeolite acid sites, the most important active centers for secondary reactions of the primary olefinic F-T products. Depending on the concentration and the strength of the acid sites, a function of the Si/Al ratio and the nature of the residual neutralizing cations, various competitive reaction paths can be observed for the transformation of olefinic compounds. These include isomerization, oligomerization, cracking, hydrogen transfer, etc. 67 figs., 32 tabs.
- Research Organization:
- Pittsburgh Univ., PA (USA). Dept. of Chemical and Petroleum Engineering
- DOE Contract Number:
- FG22-83PC60805
- OSTI ID:
- 7055533
- Report Number(s):
- DOE/PC/60805-T12; ON: DE87002505
- Country of Publication:
- United States
- Language:
- English
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10 SYNTHETIC FUELS
2-METHYLPROPANE
ADSORPTION
ALKALI METAL COMPOUNDS
ALKANES
ALKENES
BUTENES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CESIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
DATA
DIFFRACTION
ELEMENTS
EXPERIMENTAL DATA
FISCHER-TROPSCH SYNTHESIS
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROGENATION
INFORMATION
INORGANIC ION EXCHANGERS
ION EXCHANGE
ION EXCHANGE MATERIALS
ISOMERIZATION
LITHIUM COMPOUNDS
MATERIALS
METALS
METHANE
MINERALS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
PLATINUM METALS
POTASSIUM COMPOUNDS
PROMOTERS
RUBIDIUM COMPOUNDS
RUTHENIUM
SCATTERING
SEPARATION PROCESSES
SODIUM COMPOUNDS
SORPTION
SORPTIVE PROPERTIES
SPECIFICITY
STRUCTURAL CHEMICAL ANALYSIS
SURFACE PROPERTIES
SYNTHESIS
TRANSITION ELEMENTS
X-RAY DIFFRACTION
ZEOLITES