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Titolo:
Hydrothermal synthesis of co-rich CoAPO-5 molecular sieves
Autore:
Fan, WB; Schoonheydt, RA; Weckhuysen, BM;
Indirizzi:
Katholieke Univ Leuven, Dept Interfasechem, Ctr Oppervlaktechem & Katalyse, B-3001 Heverlee, Belgium Katholieke Univ Leuven Heverlee Belgium B-3001 B-3001 Heverlee, Belgium Univ Utrecht, Debye Inst, Dept Anorgan Chem & Katalyse, NL-3508 TB Utrecht, Netherlands Univ Utrecht Utrecht Netherlands NL-3508 TB 3508 TB Utrecht, Netherlands
Titolo Testata:
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
fascicolo: 15, volume: 3, anno: 2001,
pagine: 3240 - 3246
SICI:
1463-9076(2001)3:15<3240:HSOCCM>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
ELECTRON-SPIN-RESONANCE; REDOX CENTERS; COBALT; SUBSTITUTION; PHOSPHATE; CHEMISTRY; IONS; GEL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Fan, WB Katholieke Univ Leuven, Dept Interfasechem, Ctr Oppervlaktechem & Katalyse, Kardinaal Mercierlaan 92, B-3001 Heverlee, Belgium Katholieke Univ Leuven Kardinaal Mercierlaan 92 Heverlee Belgium B-3001
Citazione:
W.B. Fan et al., "Hydrothermal synthesis of co-rich CoAPO-5 molecular sieves", PHYS CHEM P, 3(15), 2001, pp. 3240-3246

Abstract

A series of CoAPO-5 materials have been hydrothermally synthesized to maximize the degree of isomorphous substitution of Co2+ ions in the AFI framework. The as-synthesized as well as the calcined CoAPO-5 materials have been characterized with XRD, SEM, ICP, DRS (diffuse reflectance spectroscopy) and FT-IR techniques. Optimum conditions for the synthesis of Co-rich CoAPO-5molecular sieves have been obtained by evaluating the influence of the amount and type of cobalt source, the type of aluminium source, the type of template molecule, the [template]:[P2O5] ratio and the amount of different monovalent cations on the isomorphous substitution of Co2+ in the lattice. Itwill be shown that highly-crystalline hexagonal CoAPO-5 crystals with a substitution degree of 12% can be obtained from a CsCl . Co(CH3COO)(2). 4H(2)O . pseudo-gamma -AlO(OH).H3PO4. (C2H5)(3)N .H2O gel (with [(C2H5)(3)N]:[P2O5] and [CsCl]:[Co(CH3COO)(2)] ratios of respectively 1.0 and 0.5) autoclaved for 41 h at 190 degreesC. In addition, the effect of monovalent cations on the redox properties of Co2+ in CoAPO-5 molecular sieves will be discussed. The degree of oxidation of framework Co2+ to Co3+ is always relatively low and increases in the order Li+<K(+)approximate to Rb(+)approximate to Cs+< NH(4)(+)approximate to Na+. Thus, the addition of Li+ results in a stabilization of Co2+ in the framework of CoAPO-5 molecular sieves upon calcination.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 11:10:03