Positions of cations and molecules in zeolites with the faujasite-type framework V. La-exchanged Type X zeolite at 25, 425 and 735°C
Review articleOpen access
1969/02/01 Full-length article DOI: 10.1016/0025-5408(69)90021-X
Journal: Materials Research Bulletin
AbstractLa-exchanged Type X zeolite activated at 500° and 600° shows three OH infra-red bands which are not completely removed even after vacuum activation at 730°C. At room temperature, the La atoms occupy sites I′, II and V. At 425 and 735°C in a helium stream the La atoms occupy sites I, I′ and II. The simplest interpretation is that La atoms tend to occupy sites I and II when X zeolite is strictly dehydrated and dehydroxylated, and that they prefer site I′ when some residual molecules are available for bonding.
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