UV Raman spectroscopic studies of V/θ-Al2O3 catalysts in butane dehydrogenation

Zili Wu, Peter C Stair

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

To explore the coke formation mechanism and catalyst structure under alkane dehydrogenation (DH) conditions, the DH of butane on V/θ-Al 2O3 was explored by in situ UV Raman spectroscopy and reactivity tests. Studies of butane DH on V/θ-Al2O3 catalysts with various distributions of surface VOx species identify a structure-coke relationship. The deactivation of the catalysts in butane DH is due mainly to the formation of coke species. Both the nature and amount of coke formed are related to the structure of VOx species. Monovanadates make chain-like polyaromatics, whereas polyvanadates produce mainly sheet-like (two-dimensional) polyaromatics that are detrimental to catalytic activity. The amount of coke formed from butane DH follows this sequence: polymeric VO x > monomeric VOx > V2O5, Al2O3. Raman spectroscopy studies of butane, 1-butene, cis/trans-2-butenes, and 1,3-butadiene reactions on V/θ-Al 2O3 catalysts enable the formulation of a coke formation pathway for butane DH, in which polystyrene is found to be a key intermediate. Although the surface of V/θ-Al2O3 is partially reduced under butane DH conditions, the structure of VOx species can be fully regenerated by oxidation of the coke species at temperatures up to 873 K.

Original languageEnglish
Pages (from-to)220-229
Number of pages10
JournalJournal of Catalysis
Volume237
Issue number2
DOIs
Publication statusPublished - Jan 25 2006

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Keywords

  • Butane
  • Coke
  • Dehydrogenation
  • Monovanadate
  • Polyaromatics
  • Polystyrene
  • Polyvanadate
  • UV Raman
  • Vanadium oxide

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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