Magnetic and Moessbauer study of metal-zeolite interaction in catalysts

Journal Article · Tue Mar 20 00:00:00 EST 1984 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.333248· OSTI ID:5230716

Pannaparayil, T; Oskooie-Tabrizi, M; Lo, C; Mulay, L N; Melson, G A; Rao, V U.S.

Molecular sieve aluminosilicates, such as ZSM-5 and mordenite, when impregnated with highly dispersed Fe, yield catalysts for the selective conversion of coal-derived syngas (CO+H/sub 2/) to liquid hydrocarbon fuels. Fe performs the primary Fischer-Tropsch (FT) syngas to yield light olefins which are converted by the acidic (H/sup +/) and shape-selective function of the zeolite to high octane gasoline components. The physical aspects of the Fe-mordenite interaction studied by magnetic measurements, Moessbauer, and IR spectroscopy are reported and correlations with the catalytic properties are drawn. Mordenite samples with (SiO/sub 2//Al/sub 2/O/sub 3/) ratio in the range 12 -- 60 were impregnated with 15 wt. % Fe using Fe/sub 3/(CO)/sub 12/; decarbonylation yielded superparamagmetic dispersions of ..gamma..-Fe/sub 2/O/sub 3/, in the range 1.4--5.0 nm; the smallest particles were obtained for a ratio = 17. Hydrogen chemisorption also revealed a similar trend in Fe dispersions. No samples, other than the one with a ratio = 60 and containing the largest particles could be carbided under usual conditions. The acidity of the mordenite and the aromatics fraction in liquid hydrocarbons from syngas conversion also showed maxima at a ratio = 17. The presence of a strong metal-support interaction between Fe and mordenite was thus influenced by the varying ratios in the mordenite in a manner that paralleled the acidity and catalytic activity.

• Research Organization: Physics Department, Pennsylvania State University, Sharon, Pennsylvania 16156
• OSTI ID: 5230716
• Journal Information: J. Appl. Phys.; (United States), Vol. 55:6
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
MORDENITE
MAGNETIZATION
MOESSBAUER EFFECT
CATALYSTS
INFRARED SPECTRA
IRON ADDITIONS
PARTICLE SIZE
ALLOYS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IRON ALLOYS
MATERIALS
MINERALS
SILICATE MINERALS
SIZE
SPECTRA
ZEOLITES
090121* - Hydrocarbon Fuels- Chemical Synthesis- (1976-1989)