The nature and catalytic activity of hydroxyl groups in clinoptilolite

Emil J. Detreköy, Peter A. Jacobs, D. Kalló, Jan B. Uytterhoeven

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

IR spectroscopy of NH4-clinoptilolite after deammoniation at 400 °C shows a single hydroxyl band at 3620 cm-1, slightly asymmetric to the lower wave numbers. The deammoniation is reversible and stoichiometric: for each NH4+ ion that decomposes an acidic hydroxyl group is formed in the lattice. At temperatures higher than 400 °C dehydroxylation occurs: two lattice hydroxyls condense, water is evacuated, and Lewis acid sites are created. Comparison of the adsorption of NH3 and pyridine on the H-clinoptilolite, shows that about 10% of the lattice hydroxyl groups are on the external surface. The catalyst is active for the isomerization of 1-butene. The isomerization activity changes with the amount of hydroxyl groups on the external surface. Lewis acid sites are created at elevated temperatures, but have no secondary influence on the catalytically active Brønsted sites.

Original languageEnglish
Pages (from-to)442-451
Number of pages10
JournalJournal of Catalysis
Volume32
Issue number3
DOIs
Publication statusPublished - 1974

Fingerprint

Isomerization
Hydroxyl Radical
catalytic activity
Catalyst activity
isomerization
Acids
Lewis Acids
Butenes
Pyridine
Infrared spectroscopy
acids
Thermodynamic properties
butenes
Adsorption
Temperature
Catalysts
pyridines
Ions
catalysts
Water

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

The nature and catalytic activity of hydroxyl groups in clinoptilolite. / Detreköy, Emil J.; Jacobs, Peter A.; Kalló, D.; Uytterhoeven, Jan B.

In: Journal of Catalysis, Vol. 32, No. 3, 1974, p. 442-451.

Research output: Contribution to journalArticle

Detreköy, Emil J. ; Jacobs, Peter A. ; Kalló, D. ; Uytterhoeven, Jan B. / The nature and catalytic activity of hydroxyl groups in clinoptilolite. In: Journal of Catalysis. 1974 ; Vol. 32, No. 3. pp. 442-451.
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