Frequency-response characterization of acid sites in zeolite catalysts using NH3 as the probe molecule

Lovat V C Rees, G. Onyestyák

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The frequency-response (FR) technique has been shown to be a novel, useful method for studying the dynamics of ammonia adsorption-desorption processes and the rates obtained can be used to characterize the acidic sites present, for example, in zeolite catalysts. The FR method has been proved to be capable of recognizing mass transfer effects and distinguishing the different strengths and concentrations of acidic sites using ammonia sorbate pressures of ≈1-10 mbar and temperatures close to those applied under real catalytic reaction conditions. The method, therefore, has advantages over techniques which require high vacuum or very low probe molecule pressures to obtain the relevant information. Combination of the FR method and other methods is necessary, however, to reach a complete characterization of all of the zeolitic acid sites present in a sample.

Original languageEnglish
Pages (from-to)293-303
Number of pages11
JournalMicroporous and Mesoporous Materials
Volume28
Issue number2
Publication statusPublished - Apr 1999

Fingerprint

Zeolites
frequency response
Frequency response
Ammonia
catalysts
acids
Catalysts
Molecules
Acids
probes
ammonia
sorbates
molecules
high vacuum
mass transfer
Desorption
Mass transfer
desorption
Vacuum
Adsorption

Keywords

  • Acid sites
  • Frequency response
  • NH
  • Zeolites FAU, MOR, MFI and BEA

ASJC Scopus subject areas

  • Catalysis
  • Materials Science(all)

Cite this

Frequency-response characterization of acid sites in zeolite catalysts using NH3 as the probe molecule. / Rees, Lovat V C; Onyestyák, G.

In: Microporous and Mesoporous Materials, Vol. 28, No. 2, 04.1999, p. 293-303.

Research output: Contribution to journalArticle

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