Surface phases in sulfided Ni-Mo/Al/sub 2/O/sub 3/ catalysts

Journal Article · Fri Jun 01 04:00:00 EDT 1984 · J. Catal.; (United States)

OSTI ID:6139853

Bachelier, J; Tilliette, M J; Duchet, J C; Cornet, D

The promoting action of nickel on sulfided Mo catalysts has been examined on two series of thiophene-sulfided Ni-Mo/Al/sub 2/O/sub 3/ catalysts with constant Mo content (7 and 16% MoO/sub 3/, respectively) and variable Ni concentration. The catalysts are characterized by their activity for thiophene HDS, by the fraction of Ni or Mo which can be extracted in an acidic or basic medium, and by their sulfur content. Comparison with one-component Ni/Al/sub 2/O/sub 3/ and Mo/Al/sub 2/O/sub 3/ catalysts shows that the dissolution of molybdenum is unaffected by the presence of nickel; by contrast, molybdenum lowers the non-extractable fraction of nickel, and thus partially hampers the migration of the promoter ions into the alumina matrix. The changes in the catalytic activity are discussed according to the amount of free (extractable) nickel Ni/sub F/: three different roles of nickel are found and related to the nature of the surface phases. In the main promotion range of the first series (p.1 < Ni/sub F//Mo < 0.6), the results are consistent with increasing formation of a Ni-Mo-S phase which consists of small Mo entities associating almost two promoter atoms to three molybdenum atoms. For the high-Mo series, interaction between the Mo units leads to a different Ni-Mo-S association in larger patches, which limits at a lower Ni/sub F//Mo ratio the favorable effect of added nickel. Higher Ni content results for both series in bulk Ni/sub 3/S/sub 2/, unsuitable for further development in activity. At low Ni/sub F//Mo ratio, the catalyst structure is not elucidated. 28 references, 5 figures, 1 table.

• Research Organization: Universitte de Caen, France
• OSTI ID: 6139853
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 87:2; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CATIONS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
DATA
ELEMENTS
EXPERIMENTAL DATA
EXTRACTION
HETEROCYCLIC COMPOUNDS
HIGH TEMPERATURE
INFORMATION
IONS
KINETICS
METALS
MOLYBDENUM
NICKEL
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PH VALUE
POLYCYCLIC SULFUR HETEROCYCLES
REACTION KINETICS
SEPARATION PROCESSES
SULFIDES
SULFUR
SULFUR COMPOUNDS
SULFUR CONTENT
SURFACE PROPERTIES
THERMODYNAMIC ACTIVITY
TRANSITION ELEMENTS