Metal-support interactions in precipitated, magnesium-promoted cobalt-silica catalysts

Journal Article · Wed Apr 01 04:00:00 EST 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90347-K· OSTI ID:6915816

Puskas, I ^[1]; Fleisch, T H; Hall, J B; Meyers, B L; Roginski, R T ^[2]

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1. Amoco Chemical Co., Naperville, IL (United States)
2. Amoco Corp., Naperville, IL (United States)

To define cobalt-silica interactions, precipitated, Mg-promoted catalysts were prepared by the cobalt nitrate-sodium carbonate reaction, without support and in the presence of silica supports. The major component of the unsupported Co catalyst was tentatively identified as Co[sub 2]CO[sub 4] on the basis of elemental analyses and the IR carbonate absorptions. Upon heating in air at 360 C, the unsupported catalyst converted to Co[sub 3]O[sub 4] according to IR and XRD analyses. TPR studies indicated easy reduction at 300-400 C, with one peak for the Co[sub 2]CO[sub 4] and the Co(OH)[sub 2] components. A Mg-promoted unsupported catalyst showed similar chemical properties and nearly identical IR spectrum: however, significantly different reducibility characteristics were observed by TPR. The composition of the silica-supported catalysts varied between two extremes. The cobalt silicates required temperatures >700 C for reduction according to TPR. The TPR of the intermediate-type catalysts that were, in part, blends of the unsupported catalyst with the silica and, in part, cobalt silicates showed cobalt silicate reductions starting above 400 C. This may be due to the catalytic effect of the cobalt that was reduced in the 300-400 C range. Electron microscopy, in combination with energy-dispersive X-ray analyses, further confirmed the cobalt-silica reaction. Cobalt silicates appeared as a 'growth,' often with a filamentous structure, leaving other areas of the silica completely intact. The formation of cobalt silicates by a solid-solute reaction is discussed.

• OSTI ID: 6915816
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 134:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

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ABSORPTION SPECTROSCOPY
ALKALINE EARTH METALS
CARBON COMPOUNDS
CARBONATES
CATALYST SUPPORTS
CATALYSTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COBALT
COBALT CARBONATES
COBALT COMPOUNDS
COBALT HYDROXIDES
COBALT OXIDES
COBALT SILICATES
COHERENT SCATTERING
CONFIGURATION INTERACTION
CONTROL
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
FISCHER-TROPSCH SYNTHESIS
HEAT TREATMENTS
HYDROGEN COMPOUNDS
HYDROXIDES
INFRARED RADIATION
MAGNESIUM
METALS
MICROSCOPY
OXIDES
OXYGEN COMPOUNDS
PROMOTERS
RADIATIONS
REDUCTION
SCATTERING
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
SYNTHESIS
TEMPERATURE CONTROL
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY