Sulfided Co--Mo/. gamma. -Al/sub 2/O/sub 3/ catalyst: evidence of structural changes during hydrodesulfurization of dibenzothiophene

Journal Article · Tue Aug 01 04:00:00 EDT 1978 · J. Catal.; (United States)

OSTI ID:6606342

Broderick, D H; Schuit, G C.A.; Gates, B C

Hydrodesulfurization (HDS) kinetics data for dibenzothiophene (DBT) were measured to characterize the Co-Mo/..gamma..-Al/sub 2/O/sub 3/ catalyst operating at 100 atm and 300/sup 0/C. The data indicate that H/sub 2/S does more than just inhibit the HDS reaction by adsorbing on catalytic sites in competition with DBT. It is presumed that an increase in space velocity reduced the H/sub 2/S concentration produced in the rxn, and resulted in structural changes in the catalyst to reduce the number of catalytic sites. The loss of catalytic sites was not completely reversed when the concentration of H/sub 2/S was again increased by decreasing the space velocity. Further data suggested that there is an optimum concentration of H/sub 2/S corresponding to a catalyst structure that has a maximum HDS activity. Data from experiments carried out to define the optimum concentration of H/sub 2/S led to the conclusion that the catalyst achieved a time-invariant activity which is dependent on the reactor start-up procedure and probably on the presulfiding procedure as well. In light of these data, it is suggested that the catalyst may consist of a range of intermediate structures which could be interconverted by local redistributions of Co and Mo ions accompanied by changes in the Mo-S surrounding.

• Research Organization: Univ. of Delaware, Newark
• OSTI ID: 6606342
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 54:1; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
023000* -- Petroleum-- Properties & Composition
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
COBALT
DESULFURIZATION
ELEMENTS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
METALS
MOLYBDENUM
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METALS
SULFIDES
SULFUR COMPOUNDS
THIONAPHTHENES
TRANSITION ELEMENTS