Statistical analysis of Al distributions and metal ion pairing probabilities in zeolites

B. R. Goodman, K. C. Hass, W. F. Schneider, James Adams

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

The distributions of Al tetrahedral sites are studied as a function of Si : Al ratio (from 11 to 95) in three zeolites: ZSM-5, ferrierite, and mordenite. Al configurations obeying Loewenstein's rule are generated by a Monte Carlo procedure and analyzed in terms of accessibility to specific channels. The distribution of pairs of Al sites accessible to the same channel segregates into distinct nearest-neighbor and ring-bridging types. Such pairs provide favorable binding environments for extraframework MOxM2+ cations in the metal-ion-exchanged forms of the zeolites. In all three zeolites, the probability of a given Al site having at least one suitable partner for pairing within 8.5 Å is close to unity for typical Si : Al ratios. The probability at shorter distances is more sensitive to the zeolite structure, reflecting the larger number of highly puckered five-and six-membered rings in ZSM-5. This sensitivity, and its implications for CuOxCu2+ formation in the three Cu-exchanged forms, may explain why Cu-ZSM-5 is the most active of the three for catalytically decomposing NO.

Original languageEnglish (US)
Pages (from-to)85-93
Number of pages9
JournalCatalysis Letters
Volume68
Issue number1-2
StatePublished - Aug 2000

Fingerprint

Zeolites
ion distribution
zeolites
statistical analysis
Metal ions
metal ions
Statistical methods
rings
unity
Positive ions
Cations
cations
sensitivity
configurations

Keywords

  • Al pairs
  • Cu oxocations
  • Ferrierite
  • Monte Carlo sampling
  • Mordenite
  • NO decomposition
  • Zeolites
  • ZSM-5

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry

Cite this

Statistical analysis of Al distributions and metal ion pairing probabilities in zeolites. / Goodman, B. R.; Hass, K. C.; Schneider, W. F.; Adams, James.

In: Catalysis Letters, Vol. 68, No. 1-2, 08.2000, p. 85-93.

Research output: Contribution to journalArticle

Goodman, B. R. ; Hass, K. C. ; Schneider, W. F. ; Adams, James. / Statistical analysis of Al distributions and metal ion pairing probabilities in zeolites. In: Catalysis Letters. 2000 ; Vol. 68, No. 1-2. pp. 85-93.
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