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Secondary porous structure of dealuminated Y zeolites

✍ Scribed by A. Zukal; V. Patzelová; U. Lohse

Publisher
Elsevier Science
Year
1986
Tongue
English
Weight
298 KB
Volume
6
Category
Article
ISSN
0144-2449

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✦ Synopsis

Six NH4Na-Y zeolite samples were treated hydrothermally under deep-bed conditions. Aluminium released from the crystal lattice during the treatment was removed by extraction with 0.1 N HCI; this extraction also removed Na + cations.

To obtain information on changes in the porous structure caused by the hydrothermal treatment, adsorption and desorption isotherms of benzene vapours were measured on these dealuminated and decationized samples. It was found that secondary mesopores are formed in the zeolite crystals at a degree of dealumination not exceeding 30%. If the degree of dealumination approaches 50%, formation of secondary micropores occurs, in addition to mesopores. The observed changes of the micropore volume suggest that the zeolitic lattice is destroyed on the mesopore surface.

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