The influence of boron and titania on Co/Al[sub 2]O[sub 3] and Mo/Al[sub 2]O[sub 3] catalysts

Thesis/Dissertation · Thu Dec 31 23:00:00 EST 1987

OSTI ID:6925402

Stranick, M A

A method is described for the use of X-ray photoelectron spectroscopy for quantitatively determining the speciation of metals in supported metal catalysts. The influence of boron on the chemical state and dispersion of Co/Al[sub 2]O[sub 3] has been investigated. In the absence of boron, Co dispersion decreased with increasing Co loading, while boron modified catalysts exhibited an increase in cobalt dispersion. In the absence of boron, Co exists as tetrahedral and octahedral Co[sup 2+] at low Co loadings, while Co[sub 3]O[sub 4] is the primary phase at higher Co loadings. For boron modified catalysts, Co[sub 3]O[sub 4] is suppressed in favor of octahedral Co[sup 2+] and Co borate. A series of TiO[sub 2]/Al[sub 2]O[sub 3] carriers and 3% Co/Al[sub 2]O[sub 3]-TiO[sub 2] catalysts have been characterized spectroscopically. It was found that titania is well dispersed on alumina for Ti loadings below 14 wt% and exists primarily as a titania-alumina surface phase. The Co[sub 3]O[sub 4] content of the 3% Co catalysts decreased with increasing TiO[sub 2] loading with a commensurate increase in octahedral cobalt-titania surface phase. The activity of the 3% Co catalysts for CO and benzene hydrogenation decreased with increasing titania loading. The influence of boron and titania on the surface structure and hydrodesulfurization activity of an 8% Mo/Al[sub 2]O[sub 3] catalyst has been investigated. Molybdenum was well dispersed on both the boron and titania modified carriers. The presence of boron and titania increased the extents of reduction and sulfidation of the Mo/Al[sub 2]O[sub 3] catalyst. The hydrodesulfurization activity of the Mo/Al[sub 2]O[sub 3]-TiO[sub 2] catalyst increased with increasing titania loading. Low loadings of boron did not effect hydrodesulfurization activity, while high boron loadings decreased catalyst activity.

• Research Organization: Pittsburgh Univ., PA (United States)
• OSTI ID: 6925402
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010402 -- Coal
Lignite
& Peat-- Purification & Upgrading
010408 -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
02 PETROLEUM
020400 -- Petroleum-- Processing
36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
AROMATICS
BENZENE
BORON
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMICAL STATE
COBALT
COBALT COMPOUNDS
COBALT OXIDES
CRYSTAL STRUCTURE
DESULFURIZATION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROCARBONS
HYDROGENATION
LOADING RATE
METALS
METHANATION
MICROSTRUCTURE
MOLYBDENUM
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
PHOTOELECTRON SPECTROSCOPY
SEMIMETALS
SPECTROSCOPY
SURFACE PROPERTIES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY SPECTROSCOPY