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Titolo:
Epoxidation of cyclic alkenes with hydrogen peroxide and tert-butyl hydroperoxide on Na-containing Ti beta zeolites
Autore:
Xia, QH; Chen, X; Tatsumi, T;
Indirizzi:
Fudan Univ, Dept Environm Sci & Engn, Shanghai 200433, Peoples R China Fudan Univ Shanghai Peoples R China 200433 nghai 200433, Peoples R China Yokohama Natl Univ, Div Mat Sci & Chem Engn, Yokohama, Kanagawa 2408501, Japan Yokohama Natl Univ Yokohama Kanagawa Japan 2408501 anagawa 2408501, Japan
Titolo Testata:
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
fascicolo: 1-2, volume: 176, anno: 2001,
pagine: 179 - 193
SICI:
1381-1169(20011120)176:1-2<179:EOCAWH>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
TITANIUM SILICALITE; CATALYTIC ACTIVITY; OXIDATION; OLEFINS; SILICATES; ALKANES;
Keywords:
Na-Ti beta; liquid-phase oxidation of cyclic alkenes; epoxidation; titanium zeolites; hydrogen peroxide; TBHP;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
27
Recensione:
Indirizzi per estratti:
Indirizzo: Xia, QH Natl Univ Singapore, Dept Chem & Environm Engn, Singapore 119260, Singapore Natl Univ Singapore Singapore Singapore 119260 119260, Singapore
Citazione:
Q.H. Xia et al., "Epoxidation of cyclic alkenes with hydrogen peroxide and tert-butyl hydroperoxide on Na-containing Ti beta zeolites", J MOL CAT A, 176(1-2), 2001, pp. 179-193

Abstract

The liquid-phase epoxidation of a series of cyclic alkenes with H2O2, and TBHP over Na-Ti beta zeolites without undergoing further acid-treatment hasbeen carefully investigated. Many factors such as the time, the conversion, the solvent, the Si/Na ratio, the Si/Ti ratio and the Ti/Na ratio, have been found to take effects on the conversion of cyclohexene and H2O2 as wellas the selectivity to epoxide. Lower conversion (about 6.2 mol%) of cyclohexene has shown an improvement for the selectivity to epoxide (about 90%). The solvent having bigger dielectric constant is very helpful to enhance the reactivity of substrate, particularly MeCN is an optimal choice for improving the selectivity to epoxide (up to 59%). The reactivity of cyclic alkenes decreases with increasing carbon number from C6 to C12, the selectivity to corresponding cyclic epoxides is C12 approximate to C8 (100%) > C7 (71%)> C5 (20%) > C6 (1.2%), where the exception of C5 is related to its low dissolubility and steric conformations of reactant and products molecules. Linear alkene shows the higher reactivity and the lower selectivity to epoxide than cyclic alkene with the same carbon number. TBHP as the oxidant significantly retards the reactivity of C6, C7 and C12, and shows more beneficial to the selective production of epoxide than H2O2 (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/09/20 alle ore 07:34:56