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Effect of lithium addition upon γ‐Al 2 O 3 for isopropanol dehydration
Author(s) -
de Miguel Sergio R.,
Caballero Martinez Alfonso,
Castro Alberto A.,
Scelza Osvaldo A.
Publication year - 1996
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/(sici)1097-4660(199602)65:2<131::aid-jctb404>3.0.co;2-u
Subject(s) - dehydration , lithium (medication) , chemistry , dimethyl ether , olefin fiber , catalysis , ether , inorganic chemistry , reaction mechanism , organic chemistry , medicine , biochemistry , endocrinology
The effect of lithium addition to γ‐Al 2 O 3 on the acidity and on the catalytic behaviour in the isopropanol dehydration reaction is studied. Results show that there is an important blocking or poisoning effect of lithium on the Lewis Al 3+ sites of the alumina surface; these sites play an important role in the isopropanol dehydration reaction to di‐isopropylether and propylene. The di‐isopropylether formation is drastically reduced by lithium addition, while the propylene formation can be maintained, even at a high lithium content, by increasing the reaction temperature. Results are interpreted by considering that the ether would be produced by a concerted mechanism (E 2 ), and the olefin formation could be carried out by both E 2 or E 1 mechanisms.