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Novel mesoporous nanocomposite WOx-silicate acidic catalysts / Dilek Varisli in Industrial & engineering chemistry research, Vol. 48 N° 21 (Novembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9394–9401 Titre : Novel mesoporous nanocomposite WOx-silicate acidic catalysts : ethylene and diethylether from ethanol Type de document : texte imprimé Auteurs : Dilek Varisli, Auteur ; Timur Dogu, Auteur ; Gulsen Dogu, Auteur Année de publication : 2010 Article en page(s) : pp. 9394–9401 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Solid  acid  catalysts  Ethylene  Diethylether  Ethanol Résumé : Solid acid catalysts are extensively used in a number of industrially important catalytic reactions. Here, water-insoluble novel mesoporous solid acid catalysts, with a unique structure composed of WOx nanorods and W nanoballs within an amorphous silicate lattice, were synthesized following a one-pot hydrothermal route, using silicotungstic acid (STA) as the active component. Surface area of these catalysts are more than 2 orders of magnitude higher than that of pure STA, and they showed very high activity for the simultaneous production of ethylene and diethylether (DEE), which is an attractive transportation fuel alternate, from a nonpetroleum feedstock, namely ethanol. Depending upon the operating conditions, ethylene or DEE selectivities approaching 1.0 or 0.8 were obtained, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008154 [article] Novel mesoporous nanocomposite WOx-silicate acidic catalysts : ethylene and diethylether from ethanol [texte imprimé] / Dilek Varisli, Auteur ; Timur Dogu, Auteur ; Gulsen Dogu, Auteur . - 2010 . - pp. 9394–9401. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9394–9401 Mots-clés : Solid  acid  catalysts  Ethylene  Diethylether  Ethanol Résumé : Solid acid catalysts are extensively used in a number of industrially important catalytic reactions. Here, water-insoluble novel mesoporous solid acid catalysts, with a unique structure composed of WOx nanorods and W nanoballs within an amorphous silicate lattice, were synthesized following a one-pot hydrothermal route, using silicotungstic acid (STA) as the active component. Surface area of these catalysts are more than 2 orders of magnitude higher than that of pure STA, and they showed very high activity for the simultaneous production of ethylene and diethylether (DEE), which is an attractive transportation fuel alternate, from a nonpetroleum feedstock, namely ethanol. Depending upon the operating conditions, ethylene or DEE selectivities approaching 1.0 or 0.8 were obtained, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8008154

Silicotungstic acid impregnated MCM-41-like mesoporous solid acid catalysts for dehydration of ethanol / Dilek Varisli in Industrial & engineering chemistry research, Vol. 47 n°12 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4071–4076 Titre : Silicotungstic acid impregnated MCM-41-like mesoporous solid acid catalysts for dehydration of ethanol Type de document : texte imprimé Auteurs : Dilek Varisli, Auteur ; Timur Dogu, Auteur ; Gulsen Dogu, Auteur Année de publication : 2008 Article en page(s) : p. 4071–4076 Note générale : Bibliogr. p. 4076 Langues : Anglais (eng) Mots-clés : Mesoporous  solid  acid;  Impregnation;  Ethanol  dehydration Résumé : In this study, mesoporous nanocomposite silicotungstic acid (STA) incorporated MCM-41 and mesoporous aluminosilicate catalysts with narrow pore size distributions, in the range of 2.5–3.5 nm, were successfully synthesized following different impregnation procedures. Results showed that the catalyst preparation procedure had significant influence on its activity as well as the product distribution in ethanol dehydration. STAMCM41C catalyst, which was prepared by the impregnation of STA into calcined MCM-41 containing a W/Si ratio of 0.24, and STAMAS catalyst, which was prepared by the impregnation of STA into mesoporous aluminosilicate, showed very high activities in dehydration of ethanol. Ethylene yield showed an increasing trend with temperature, reaching to about 100% above 250 °C. In contrast to ethylene, DEE was formed at lower temperatures, reaching to a yield value of about 70% at 180 °C with STAMCM41C. DEE formation at lower temperatures was concluded to be due to the presence of Bronsted acid sites of this catalyst. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800192t [article] Silicotungstic acid impregnated MCM-41-like mesoporous solid acid catalysts for dehydration of ethanol [texte imprimé] / Dilek Varisli, Auteur ; Timur Dogu, Auteur ; Gulsen Dogu, Auteur . - 2008 . - p. 4071–4076. Bibliogr. p. 4076 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4071–4076 Mots-clés : Mesoporous  solid  acid;  Impregnation;  Ethanol  dehydration Résumé : In this study, mesoporous nanocomposite silicotungstic acid (STA) incorporated MCM-41 and mesoporous aluminosilicate catalysts with narrow pore size distributions, in the range of 2.5–3.5 nm, were successfully synthesized following different impregnation procedures. Results showed that the catalyst preparation procedure had significant influence on its activity as well as the product distribution in ethanol dehydration. STAMCM41C catalyst, which was prepared by the impregnation of STA into calcined MCM-41 containing a W/Si ratio of 0.24, and STAMAS catalyst, which was prepared by the impregnation of STA into mesoporous aluminosilicate, showed very high activities in dehydration of ethanol. Ethylene yield showed an increasing trend with temperature, reaching to about 100% above 250 °C. In contrast to ethylene, DEE was formed at lower temperatures, reaching to a yield value of about 70% at 180 °C with STAMCM41C. DEE formation at lower temperatures was concluded to be due to the presence of Bronsted acid sites of this catalyst. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800192t