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Solid-state NMR studies of framework defects in thermally treated zeolite Ca-A

✍ Scribed by D. Freude; J. Haase; J. Klinowski

Publisher
Elsevier Science
Year
1987
Tongue
English
Weight
399 KB
Volume
133
Category
Article
ISSN
0009-2614

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✦ Synopsis

%i 27Al and 'H magic-angle-spinning NMR and relaxation measurements on thermally treated zeolite Na,$a, ,,-A have been carried out in order to study framework defects responsible for, and surface barriers to, molecular diffusion. Various possible mechanisms for the formation of such defects are considered in detail. We conclude that no framework dealumination takes place and no acidic hydroxyl groups are present in the zeolite. Excess aluminium occluded in the as-prepared zeolite A is responsible for the production of aluminium hydroxide during hydrothermal treatment.

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