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Titolo:
Synthesis, pore texture and surface acid-base character of TiO2/carbon composite xerogels and aerogels and their carbonized derivatives
Autore:
Maldonado-Hodar, FJ; Moreno-Castilla, C; Rivera-Utrilla, J;
Indirizzi:
Univ Granada, Fac Ciencias, Dept Quim Inorgan, Grp Invest Carbones, E-18071 Granada, Spain Univ Granada Granada Spain E-18071 vest Carbones, E-18071 Granada, Spain
Titolo Testata:
APPLIED CATALYSIS A-GENERAL
fascicolo: 1, volume: 203, anno: 2000,
pagine: 151 - 159
SICI:
0926-860X(20000918)203:1<151:SPTASA>2.0.ZU;2-M
Fonte:
ISI
Lingua:
ENG
Soggetto:
SNO-2-BASED BINARY CATALYSTS; METAL-OXIDE SURFACES; RESIN HYBRID FIBERS; OXIDATION ACTIVITY; ORGANIC AEROGELS; TITANIA; SILICA; PRECURSORS; POLYCONDENSATION; DEGRADATION;
Keywords:
TiO2/C composite aerogels; TiO2/C composite xerogels; acid-base surface characteristics; tungsten supported on TiO2/C composite aerogel;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Moreno-Castilla, C Univ Granada, Fac Ciencias, Dept Quim Inorgan, Grp Invest Carbones, E-18071 Granada, Spain Univ Granada Granada Spain E-18071 071 Granada, Spain
Citazione:
F.J. Maldonado-Hodar et al., "Synthesis, pore texture and surface acid-base character of TiO2/carbon composite xerogels and aerogels and their carbonized derivatives", APP CATAL A, 203(1), 2000, pp. 151-159

Abstract

Synthesis of TiO2/C composite xerogels and aerogels were obtained by polymerization of a mixture of resorcinol, formaldehyde and tetrabutyl orthotitanate. Samples so obtained were dried with supercritical CO2 (aerogel) or at110 degrees C in an oven (xerogel). The aerogel was prepared with two different initial TiO2 contents of 30 and 49%. Both aerogels and thr xerogel were subsequently carbonized in an inert atmosphere at 500 and 900 degrees C. Surface area and porosity of the samples were measured by CO2 adsorption at 273 K and mercury porosimetry; X-ray diffraction (MD) technique was used to determine the crystallographic structure of the inorganic constituent ofthe composite (anatase or rutile); and acid-base surface characteristics of these materials were studied by testing them as catalysts in the decomposition reaction of isopropanol. Finally, some of these samples were used as supports for tungsten oxide catalysts and also tested in the above reaction. The composite aerogel with the lower TiO2 content and its carbonized derivatives had the more developed meso- and macroporosity, indicative of the importance of both the supercritical drying process of these materials and of the TiO2 content. In this case, the composite aerogel carbonized at 500 degrees C had the highest activity of propene production and therefore, the highest surface acidity, because of the good accessibility of the surface acid sites. The tungsten oxide catalyst supported on it also presented the highest conversion in the above reaction, although in this case acetone and diisopropyl ether were also obtained. (C) 2000 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 09/07/20 alle ore 17:37:18