Solid state MAS NMR investigation of Y-type zeolites reacted with chlorofluorocarbons

I. Hannus, Z. Kónya, J. B. Nagy, P. Lentz, I. Kiricsi

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

29Si, 27Al and 23Na MAS NMR techniques are used to investigate Y-type zeolites before and after reaction with CFCs (CCl4, CCl3F, CCl2F2, CClF3, CF4) and a HCFC (CHClF2). 27Al NMR spectra prove the existence of an intermediate aluminum species (distorted tetrahedral or pentacoordinated) at about 30 ppm starting from tetrahedral framework position and leading to octahedral extra framework position during the dealumination process. The presence of C-Cl bond is essential for the decomposition of CFCs, but two chlorine atoms are required for the formation of effective phosgene intermediate. HY zeolite is the least resistant to the proposed CFC compounds. On the bases of multinuclear NMR results a mechanism is given for the decomposition of CFCs. The reaction of the HCFC with zeolites follows a different mechanism. In this reaction the Y-type zeolites with basic centers are also active.

Original languageEnglish
Pages (from-to)157-166
Number of pages10
JournalApplied Catalysis B: Environmental
Volume17
Issue number1-2
DOIs
Publication statusPublished - Jun 30 1998

Fingerprint

Chlorofluorocarbons
Zeolites
MAS
CFC
nuclear magnetic resonance
Nuclear magnetic resonance
hydrochlorofluorocarbon
Phosgene
decomposition
Decomposition
Chlorine
Aluminum
zeolite
chlorine
aluminum
Atoms
solid state

Keywords

  • Na MAS NMR
  • Al
  • Si
  • CFCs
  • HCFC
  • Y-FAU zeolite

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology
  • Environmental Chemistry

Cite this

Solid state MAS NMR investigation of Y-type zeolites reacted with chlorofluorocarbons. / Hannus, I.; Kónya, Z.; Nagy, J. B.; Lentz, P.; Kiricsi, I.

In: Applied Catalysis B: Environmental, Vol. 17, No. 1-2, 30.06.1998, p. 157-166.

Research output: Contribution to journalArticle

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AU - Kiricsi, I.

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