Magnetic and Moessbauer study of metal-zeolite interaction in catalysts

Journal Article · Mon Mar 19 23:00:00 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), Journal Name: J. Appl. Phys.; (United States) Vol. 55:6; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

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