Structure of alumina-supported molybdenum disulfide hydrodesulfurization catalysts
Thesis/Dissertation
·
OSTI ID:7249058
The morphology of monolayer quantities of molybdenum oxide and sulfide phases supported on nonporous alumina and graphite thin films was studied by various electron microscopic techniques, including conventional, scanning, and controlled-atmosphere electron microscopy. When molybdenum oxide was supported on alumina, a strong oxide-support interaction was observed, resulting in a highly-dispersed molybdenum phase for loadings below ca. 5 Mo atoms nm/sup -2/. When supported on graphite, the support interaction was weaker and bulk molybdenum oxide formed that became mobile on the surface at temperatures higher than 930 K. This behavior can be explained by the relatively low surface energies for MoO/sub 3/ and graphite compared to the high surface energy for Al/sub 2/O/sub 3/. On the alumina support, the molybdenum oxide support interaction was broken by sulfiding in H/sub 2/S/H/sub 2/ at ca. 750 K, with the formation of facetted single crystallites of MoS/sub 2/. The MoS/sub 2/ crystallites were present as hexagonally-shaped slabs with one truncated edge, and were bonded with their high-energy edge planes at various angles of orientation with respect to the alumina surface. After 910 K sulfidation, the particles became larger, and many were oriented with their basal planes parallel to the support. Reoxidation at temperatures greater than 645 K redispersed the crystallites due to spreading of molybdenum oxide over alumina.
- Research Organization:
- Wisconsin Univ., Madison (USA)
- OSTI ID:
- 7249058
- Country of Publication:
- United States
- Language:
- English
Similar Records
Studies of the structure of molybdenum oxide and sulfide supported on thin films of alumina
Direct observation by controlled atmosphere electron microscopy of the changes in morphology of molybdenum oxide and sulfide supported on alumina and graphite
A Raman and XPS investigation of supported molybdenum oxide thin films. 2. Reactions with hydrogen sulfide
Journal Article
·
Sat Jan 31 23:00:00 EST 1987
· J. Catal.; (United States)
·
OSTI ID:5648324
Direct observation by controlled atmosphere electron microscopy of the changes in morphology of molybdenum oxide and sulfide supported on alumina and graphite
Journal Article
·
Mon Jun 01 00:00:00 EDT 1987
· J. Catal.; (United States)
·
OSTI ID:5450173
A Raman and XPS investigation of supported molybdenum oxide thin films. 2. Reactions with hydrogen sulfide
Journal Article
·
Thu Oct 21 00:00:00 EDT 1993
· Journal of Physical Chemistry; (United States)
·
OSTI ID:5664809
Related Subjects
01 COAL, LIGNITE, AND PEAT
010402* -- Coal
Lignite
& Peat-- Purification & Upgrading
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON
CATALYST SUPPORTS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DESULFURIZATION
ELECTRON MICROSCOPY
ELEMENTAL MINERALS
ELEMENTS
ENERGY
FREE ENERGY
GRAPHITE
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
KINETICS
MICROSCOPY
MICROSTRUCTURE
MINERALS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
MOLYBDENUM SULFIDES
MORPHOLOGY
NONMETALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
REGENERATION
SULFIDATION
SULFIDES
SULFUR COMPOUNDS
SURFACE ENERGY
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
010402* -- Coal
Lignite
& Peat-- Purification & Upgrading
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON
CATALYST SUPPORTS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
DESULFURIZATION
ELECTRON MICROSCOPY
ELEMENTAL MINERALS
ELEMENTS
ENERGY
FREE ENERGY
GRAPHITE
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
KINETICS
MICROSCOPY
MICROSTRUCTURE
MINERALS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
MOLYBDENUM SULFIDES
MORPHOLOGY
NONMETALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
REGENERATION
SULFIDATION
SULFIDES
SULFUR COMPOUNDS
SURFACE ENERGY
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS