Magnetic, Moessbauer, and catalytic properties of the zeolite catalyst ZSM-5(Fe)
Iron-impregnated medium pore zeolite ZSM-5 (pore opening of 5.5 A) is an efficient catalyst for the conversion of synthesis gas (CO+H/sub 2/) to high octane gasoline. Activity and selectivity of the ZSM-5 (Fe) depends upon the manner in which Fe is impregnated on ZSM-5. Magnetic and Moessbauer studies were conducted on catalysts prepared by two methods: (a) ferric nitrate impregnation and (b) carbonyl Fe/sub 3/(CO)/sub 12/ impregnation on the zeolite. These studies were conducted for various stages of preparation and after use of the catalysts. The carbonyl impregnated sample in the as-prepared form contained ultrafine ..gamma..-Fe/sub 2/O/sub 3/ of d = 60--66 A, as evidenced by superparamagnetic behavior seen in magnetic and Moessbauer studies. In contrast, the as-prepared, nitrate impregnated sample showed ..cap alpha..-Fe/sub 2/O/sub 3/ of approximate particle size of 100 A. Both samples were reduced to about 80% metallic Fe in flowing H/sub 2/. On exposure to synthesis gas, the carbonyl impregnated sample yielded a substantial amount of Fe/sub 3/O/sub 4/ in addition to chi carbide, wheres the nitrate impregnated sample exhibited epsilon, chi, and theta carbides. The steady catalytic activity and selectivity of the carbonyl impregnated sample can be related to the ultrafine iron dispersions leading to the observed phases in the used catalyst.
- Research Organization:
- Department of Physics, Pennsylvania State University, McKeesport, Pennsylvania 15132
- DOE Contract Number:
- AC22-81PC41265
- OSTI ID:
- 5538317
- Journal Information:
- J. Appl. Phys.; (United States), Vol. 53:3
- Country of Publication:
- United States
- Language:
- English
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PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON MONOXIDE
CHEMICAL REACTIONS
GASOLINE
SYNTHESIS
HYDROGEN
IRON COMPOUNDS
IMPREGNATION
IRON NITRATES
ZEOLITES
CATALYTIC EFFECTS
MAGNETIC PROPERTIES
MOESSBAUER EFFECT
OCTANE
ALKANES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ELEMENTS
FUELS
HYDROCARBONS
INORGANIC ION EXCHANGERS
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LIQUID FUELS
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MINERALS
NITRATES
NITROGEN COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PETROLEUM PRODUCTS
PHYSICAL PROPERTIES
TRANSITION ELEMENT COMPOUNDS
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