EFFECT OF FLUORINE TREATMENT ON THE STRUCTURE, ACIDITY AND CATALYTIC ACTIVITY OF BETA ZEOLITE

Abstract

Abstract: The Beta zeolite was modified with NH₄F/NH₃.H₂O solution, and the effect of fluorine modification on the structure, acidity and catalytic alkylation activity of the Beta zeolite was investigated. The results show that after being treated with NH₄F/NH₃.H₂O solution, the non-framework aluminum of Beta zeolite was removed and the ratio of n(SiO₂)/n(Al₂O₃) was increased. The total acid, L acid and B acid of Beta zeolite were relatively reduced, but the ratio of B acid to total acid was increased. The mesoporous specific surface area and mesopore volume of Beta zeolite were increased, which improved its adsorption capacity for organic vapor molecules and was favorable for the contact of feed molecules with the acidic sites of zeolite. Therefore, the performance of Beta zeolite catalyst for the alkylation reaction was improved by fluorine modification.

Key words: ammonium fluorine, Beta zeolite, alkylation, 2,4,6-trimethylpyridine

References

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