A sup 57 Co Moessbauer emission spectrometric study of some supported CoMo hydrodesulfurization catalysts

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90189-O· OSTI ID:6999031

Veen, J A.R. van; Hendriks, P A.J.M.; Beens, H ^[1]; Gerkema, E; Kraan, A.M. van der ^[2]

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1. Koninklijke/Shell-Lab., Amsterdam (Netherlands)
2. Delft Univ. of Technology (Netherlands)

A suite of 11 CoMo/Al{sub 2}O{sub 4} (and one CoMo/SiO{sub 2}) catalysts has been prepared employing four preparation routes, viz. one sequential-impregnation route and three different coimpregnation routes. Speciation of the Co present in the oxidic precursors (octahedral vs tetrahedral Co) and in the activated, sulfided catalysts (CoMoS, Co{sub 9}S{sub 8}, and unsulfided Co) was effected with the aid of {sup 57}Co Moessbauer emission spectroscopy (MES). A linear relation between the thiophene-hydrodesulfurization (HDS) activity and wt% Co-in-CoMoS was observed for each preparation route, but no unique correlation was found to exist. This was traced to the fact that the preparation routes differ in the amount of CoMoS I and CoMoS II they produce in the activated catalyst. Although these two phases differ in specific activity, CoMoS II being twice as active in thiophene HDS as CoMoS I, they cannot be distinguished on the basis of their Moessbauer parameters. It appears that octahedral Co is easier to sulfide than tetrahedral Co, but a substantial fraction of the latter is also found to be capable of entering CoMoS upon sulfidation. The reduced effectiveness of high-loading catalysts is traced to their being prone to CoMoO{sub 4} formation in the calcination step. A rationalization of this behavior is offered.

• OSTI ID: 6999031
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 133:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010402 -- Coal
Lignite
& Peat-- Purification & Upgrading
02 PETROLEUM
020400 -- Petroleum-- Processing
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BETA DECAY RADIOISOTOPES
BIMETALS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COBALT
COBALT 57
COBALT COMPOUNDS
COBALT ISOTOPES
COBALT SULFIDES
DAYS LIVING RADIOISOTOPES
DESULFURIZATION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EMISSION SPECTROSCOPY
HETEROCYCLIC COMPOUNDS
IMPREGNATION
INTERMEDIATE MASS NUCLEI
ISOTOPES
METALS
MOESSBAUER EFFECT
MOLYBDENUM
MOLYBDENUM COMPOUNDS
MOLYBDENUM SULFIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE STUDIES
QUANTITY RATIO
RADIOISOTOPES
REFRACTORY METAL COMPOUNDS
SILICON COMPOUNDS
SILICON OXIDES
SPECTROSCOPY
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
THIOPHENE
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS