The structure and activity of titania supported cobalt catalysts

Journal Article · Fri May 01 04:00:00 EDT 1992 · Journal of Catalysis; (United States)

OSTI ID:6976958

Suiwen, Ho; Houalla, M; Hercules, D M ^[1]; Cruz, J M ^[2]

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1. Univ. of Pittsburgh, PA (United States)
2. Intervep, S.A., Apdo, Caracas (Venezuela)

A series of titania supported cobalt catalysts (0.5-6%) were prepared by incipient wetness impregnation, and were characterized by ESCA, XRD, and hydrogen chemisorption. After calcination at 400 C, a surface CoTiO[sub 3]-like phase was the main species present in the 0.5 and 1% cobalt catalysts. For higher cobalt loadings, discrete Co[sub 3]O[sub 4] particles were formed in addition to surface CoTiO[sub 3]. ESCA indicates that after reduction the cobalt metal particle size (6-13 nm) increases with increasing cobalt loadings, but does not vary with reduction temperature (400-500 C). Hydrogen chemisorption was found to be activated and suppressed. The extent of hydrogen chemisorption suppression increases with increasing reduction temperature and decreasing cobalt particle size. The turnover frequency (based on cobalt dispersion derived from ESCA) for benzene and CO hydrogenation decreases with increasing reduction temperature and decreasing cobalt particle size. The decline in activity correlates with the extent of suppression of H[sub 2] chemisorption. The results were interpreted in terms of a decrease in the fraction of exposed surface cobalt due to site blocking by reduced TiO[sub 3] moieties.

• OSTI ID: 6976958
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 135:1; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408 -- Coal
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& Peat-- C1 Processes-- (1987-)
02 PETROLEUM
020400 -- Petroleum-- Processing
36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
AROMATICS
BENZENE
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
COBALT
COBALT COMPOUNDS
COBALT OXIDES
COHERENT SCATTERING
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROCARBONS
HYDROGEN
HYDROGENATION
IMPREGNATION
KINETICS
METALS
METHANATION
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PHASE STUDIES
REACTION KINETICS
SCATTERING
SEPARATION PROCESSES
SIZE
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
SYNTHESIS
TITANATES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION