The hydroconversion of n-heptane over reduced and oxidized Pt/H-zeolite catalysts

J. Valyon, J. Engelhardt, F. Lónyi, Z. Sándor

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The low-temperature (2 or pre-reduced in H2 at 773 K. H2-TPR results suggest that the high-silica content Pt,H-zeolites contain (Pt2O)2+ species which are reduced to Pt° in two consecutive steps. When sample was evacuated, the OH-groups of the zeolite oxidized most of the Pt° atoms close to Pt2+. The oxidation state of the Pt atoms was characterized also by IR spectroscopy using CO as a probe. It was shown that in contact with C7/H2 mixture, most Pt species did not maintain its original oxidized (Pt2+) or reduced (Pt°) state. Data suggest that pre-oxidized and pre-reduced catalysts contain Pt(1+δ)+ and Ptδ+ species, respectively, under reaction conditions. It is suggested that the reaction chain of n-C7 conversion is initiated and terminated in a redox type process over Pt(1+δ+) while in the presence of Ptδ+ the conventional bifunctional mechanism may prevail.

Original languageEnglish
Pages (from-to)375-382
Number of pages8
JournalStudies in Surface Science and Catalysis
Volume125
Publication statusPublished - 1999

Fingerprint

Zeolites
Heptane
heptanes
catalysts
Atoms
Catalysts
Carbon Monoxide
zeolites
Silicon Dioxide
atoms
Infrared spectroscopy
Silica
silicon dioxide
Oxidation
oxidation
probes
spectroscopy
Temperature
n-heptane
hydroxide ion

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Catalysis

Cite this

The hydroconversion of n-heptane over reduced and oxidized Pt/H-zeolite catalysts. / Valyon, J.; Engelhardt, J.; Lónyi, F.; Sándor, Z.

In: Studies in Surface Science and Catalysis, Vol. 125, 1999, p. 375-382.

Research output: Contribution to journalArticle

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AU - Engelhardt, J.

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