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Titolo:
Beckmann rearrangement of cyclohexanone oxime over borate-pillared LDHs
Autore:
Lin, JT; Tsai, SJ; Cheng, SF;
Indirizzi:
Natl Taiwan Univ, Dept Chem, Taipei 106, Taiwan Natl Taiwan Univ Taipei Taiwan 106 n Univ, Dept Chem, Taipei 106, Taiwan
Titolo Testata:
JOURNAL OF THE CHINESE CHEMICAL SOCIETY
fascicolo: 5, volume: 46, anno: 1999,
pagine: 779 - 787
SICI:
0009-4536(199910)46:5<779:BROCOO>2.0.ZU;2-3
Fonte:
ISI
Lingua:
ENG
Soggetto:
LAYERED DOUBLE HYDROXIDES; ANIONIC CLAY-MINERALS; HYDROTALCITE; CATALYSTS; DECOMPOSITION; DEACTIVATION; CAPROLACTAM; DERIVATIVES; PRECURSORS;
Keywords:
Beckmann rearrangement; Boria; LDH; pillaring; catalyst;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
24
Recensione:
Indirizzi per estratti:
Indirizzo: Cheng, SF Natl Taiwan Univ, Dept Chem, Taipei 106, Taiwan Natl Taiwan Univ Taipei Taiwan 106 pt Chem, Taipei 106, Taiwan
Citazione:
J.T. Lin et al., "Beckmann rearrangement of cyclohexanone oxime over borate-pillared LDHs", J CHIN CHEM, 46(5), 1999, pp. 779-787

Abstract

Berate-pillared layered double hydroxides (LDHs) were studied as catalystsin vapor-phase Beckmann rearrangement of cyclohexanone oxime to caprolactam under atmospheric pressure. The results were compared with those over thephysical admixture of LDH and boria, the co-precipitate of B-Mg-Al hydroxide, and the pristine LDH and boria compounds. Although oxime conversion andcaprolactam selectivity declined with time-on-stream over all the catalysts, berate-pillared LDH catalysts could retain activity longer than pure boria or those prepared by other methods; The decay rate however was affected by the Mg/Al ratio, the boron content and the form of LDH precursor used. The LDH itself functioning as a basic catalyst contributed to the formation of side products such as cyclohexanone and 2-cyclohexen-1-one. The physicaladmixtures of LDH and boria had catalytic properties more close to that ofpure boria, which gave high caprolactam selectivities but lost the activity in several Flours on stream. The high resistance to decay of the pillaredcatalysts was attributed to that boria in the interlayer of LDH was stabilized and prevented from structural transformation to a glassy state of no activity.

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Documento generato il 18/11/17 alle ore 05:52:15