Dehydrogenation of ethylbenzene over highly active and stable perovskite oxide catalyst - Effect of lattice oxygen on/in perovskite oxide and role of A/B site in perovskite oxide

Ryo Watanabe, Yasushi Sekine, Jungo Kojima, Masahiko Matsukata, Eiichi Kikuchi

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Previously we reported that La0.8Ba0.2Fe 0.4Mn0.6O3-δ (LBFMO) perovskite oxide catalyst showed extremely high activity for dehydrogenation of ethylbenzene to produce styrene. The reaction mechanism of dehydrogenation of ethylbenzene over LBFMO catalyst and the role of A/B site cation in the perovskite were investigated using transient response experiments and thermogravimetric analyses in a H2O/H2 atmosphere. Results showed that the dehydrogenation of ethylbenzene over LBFMO perovskite catalyst proceeded via reduction-oxidation (redox) of the perovskite oxide in this temperature range (800-900 K). Thereby, oxidative dehydrogenation of ethylbenzene consumed lattice oxygen in the perovskite; the consumed lattice oxygen was regenerated by H 2O. We measured the lattice oxygen release rate and regenerating rate over LBFMO perovskite catalyst. The regeneration rate of lattice oxygen was almost equal to the formation rate of styrene in the steady state of the dehydrogenation reaction. Substituting the B site of perovskite with Fe has a stabilizing effect for the lattice oxygen in the perovskite, and enhanced the regeneration rate of lattice vacancy drastically using steam. We concluded that the better stability of LBFMO than that of other catalysts was derived from enhanced lattice oxygen regeneration in the perovskite.

Original languageEnglish
Pages (from-to)66-72
Number of pages7
JournalApplied Catalysis A: General
Volume398
Issue number1-2
DOIs
Publication statusPublished - 2011 May 15

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Keywords

  • Dehydrogenation of ethylbenzene
  • Lattice oxygen
  • Perovskite oxides
  • Redox properties

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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