Activation of Unsupported and Al 2O3 Supported Co-Mo Catalysts In Thiophene Hydrodesulfurization

Tamás I. Korányi, Z. Paál

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Thiophene hydrodesulfurization (HDS) activities and product distributions obtained over unsupported and alumina supported impregnated oxidic Co-Mo catalysts of different mole fraction r = Co/(Co+Mo) were studied at 673 K and atmospheric pressure. The catalysts were calcined and prereduced. The highest thiophene HDS activity was attributed to a cobalt oxythiomolybdate phase detected also by X-ray diffraction. Sulfidation by thiophene is never quantitative, as shown by three independent measurements. At least two reaction routes seem likely on unsupported catalysts, as concluded from ratios of butene isomers in the products. Most active HDS sites produce 1-butene and cis-2-butene in slight excess. Extensive sulfidation leading to the formation of separate MoS 2, Co 9 S 8 and elementary sulfur seen by electron microscopy, surface cobalt enrichment, carbonization and decrease of specific surface area are discussed as possible reasons for deactivation of unsupported catalysts. Upon deactivation, the reaction route producing 1-butene becomes predominant and the decrease of the number of active sites brings about trans-2-butene excess. Alumina support prevents extensive deactivation, presumably due to stabilization of the most active species by active phase-support interactions.

Original languageEnglish
Pages (from-to)261-281
Number of pages21
JournalStudies in Surface Science and Catalysis
Volume53
Issue numberC
DOIs
Publication statusPublished - 1989

Fingerprint

Thiophenes
Hydrodesulfurization
butenes
Thiophene
thiophenes
Butenes
Chemical activation
activation
catalysts
Catalysts
Aluminum Oxide
deactivation
sulfidation
Cobalt
Alumina
cobalt
aluminum oxides
routes
Carbonization
Sulfur

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Catalysis
  • Physical and Theoretical Chemistry
  • Materials Chemistry
  • Surfaces, Coatings and Films

Cite this

Activation of Unsupported and Al 2O3 Supported Co-Mo Catalysts In Thiophene Hydrodesulfurization. / Korányi, Tamás I.; Paál, Z.

In: Studies in Surface Science and Catalysis, Vol. 53, No. C, 1989, p. 261-281.

Research output: Contribution to journalArticle

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