Raman spectroscopic study of Co-Mo/. gamma. -Al/sub 2/O/sub 3/ catalysts

Journal Article · Sat Jul 01 00:00:00 EDT 1978 · J. Catal.; (United States)

OSTI ID:5382669

Medema, J ^[1]; Beer, V H.J. de; Van Stam, C; Konings, A J.A.; Koningsberger, D C

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1. Neth. Natl. Def. Organ., Rijswijk

Laser Raman spectra of oxide precursors of hydrodesulfurization catalysts containing 0-30% molybdenum trioxide and/or 0-10% cobalt oxide on two alumina and two silica supports showed that with increasing molybdenum coverage of the support the molybdenum formed monomeric molybdate tetrahedra (MoO/sub 4/), polymolybdate with distorted octahedra (polymeric MoO/sub 4/), subsurface aluminum molybdate (Al/sub 2/MoO/sub 4/)/sub 3/, and free molybdenum trioxide (MoO/sub 3/) as distorted actahedra; that cobalt forms spinel (CoAl/sub 2/O/sub 4/) and tetrahedrally coordinated cobalt(II) (Co/sub 3/O/sub 4/), of which the latter increases with increasing cobalt coverage of the support; and that with increasing cobalt content of alumina-supported molybdenum, cobalt first forms subsurface cobalt-aluminum spinel, then a small amount of microcrystalline Co/sub 3/O/sub 4/, then subsurface cobalt molybdate (CoMoO/sub 4/) at the expense of subsurface aluminum molybdate.

• OSTI ID: 5382669
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 53:3; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COBALT COMPOUNDS
COBALT OXIDES
DESULFURIZATION
EVALUATION
HYDROGENATION
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
OXIDES
OXYGEN COMPOUNDS
RAMAN SPECTRA
REACTION INTERMEDIATES
SILICON COMPOUNDS
SILICON OXIDES
SPECTRA
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS