Title of article :
Preparation of a composite γ-zirconium phosphate-silica with large specific surface and its first characterisation as acid catalyst Original Research Article
Author/Authors :
G. Alberti، نويسنده , , S. Cavalaglio، نويسنده , , F. Marmottini، نويسنده , , K. Matusek، نويسنده , , J. Megyeri، نويسنده , , L. Szirtes، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2001
Pages :
10
From page :
219
To page :
228
Abstract :
A composite of γ-zirconium phosphate (γ-ZrP) and silica (40% in weight of γ-ZrP) was prepared by hydrolysis of tetraethylsilicate in the presence of exfoliated γ-ZrP. The exfoliation of γ-ZrP was obtained in 1:1 (v/v) acetone/water solution at 80°C. The presence of silica prevented the re-aggregation of the exfoliated γ-ZrP lamellae. After heating at 650°C, the greater part of γ-ZrP was present in the composite as bilamellar packets of zirconium phosphate acid pyrophosphate while about 20% was transformed into α-Zr(O3POH)2. The surface acid POH groups of these lamellar species (about 1.1 meq. g−1) were not destroyed by thermal treatment up to 750°C. The composite exhibited a specific surface area of 421 m2 g−1 of which about 191 m2 g−1 was attributable to exfoliated lamellae of zirconium phosphate.The catalytic properties of the composite were preliminarily investigated for the conversion of ethylbenzene to styrene at different temperatures and different EB/O(air) ratios as a function of the contact time. The results are compared with pure γ-ZrP calcined at 650°C. Catalytic activity was strongly influenced by the total amount of the surface acidic groups of the samples. The γ-ZrP/SiO2 composite showed a higher conversion rate (about five times) than calcined γ-ZrP.
Keywords :
Zirconium , Catalysis , Ethylbenzene , Phosphate , Oxidative dehydrogenation
Journal title :
Applied Catalysis A:General
Serial Year :
2001
Journal title :
Applied Catalysis A:General
Record number :
1150848
Link To Document :
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