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Seed-induced crystallization of nanosized Na-ZSM-5 crystals / Gerardo Majano in Industrial & engineering chemistry research, Vol. 48 N° 15 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7084–7091 Titre : Seed-induced crystallization of nanosized Na-ZSM-5 crystals Type de document : texte imprimé Auteurs : Gerardo Majano, Auteur ; Ali Darwiche, Auteur ; Svetlana Mintova, Auteur Année de publication : 2009 Article en page(s) : pp. 7084–7091 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : ZSM-5  nanocrystals  Nanosized  tetrapropylammonium  Seed  pretreatment Résumé : ZSM-5 nanocrystals were synthesized from organic-template-free gel systems containing 0.1, 1.0, and 3.0 wt % of 80 nm silicalite-1 seeds. The syntheses were performed at 100, 120, 150, and 170 °C for periods of time ranging between 3 and 190 h. Physicochemical characteristics derived from XRD, NMR, TG/DTA, SEM/TEM, DLS, N2 adsorption and chemical analyses of Na-ZSM-5 nanocrystals were compared with those of the nanosized tetrapropylammonium (TPA)-promoted counterpart. Crystalline yield and colloidal stability of ZSM-5 nanosized materials obtained under different conditions (seed content, crystallization temperature, and time) were also studied. Another issue of interest in the framework of this study was the effect of seed pretreatment (drying, calcination) on the characteristics of crystalline product. Thus, factors controlling seeded growth of nanosized zeolite particles were established and the mechanism of formation, including parameters governing the formation of single or aggregated crystals, revealed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8017252 [article] Seed-induced crystallization of nanosized Na-ZSM-5 crystals [texte imprimé] / Gerardo Majano, Auteur ; Ali Darwiche, Auteur ; Svetlana Mintova, Auteur . - 2009 . - pp. 7084–7091. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 15 (Août 2009) . - pp. 7084–7091 Mots-clés : ZSM-5  nanocrystals  Nanosized  tetrapropylammonium  Seed  pretreatment Résumé : ZSM-5 nanocrystals were synthesized from organic-template-free gel systems containing 0.1, 1.0, and 3.0 wt % of 80 nm silicalite-1 seeds. The syntheses were performed at 100, 120, 150, and 170 °C for periods of time ranging between 3 and 190 h. Physicochemical characteristics derived from XRD, NMR, TG/DTA, SEM/TEM, DLS, N2 adsorption and chemical analyses of Na-ZSM-5 nanocrystals were compared with those of the nanosized tetrapropylammonium (TPA)-promoted counterpart. Crystalline yield and colloidal stability of ZSM-5 nanosized materials obtained under different conditions (seed content, crystallization temperature, and time) were also studied. Another issue of interest in the framework of this study was the effect of seed pretreatment (drying, calcination) on the characteristics of crystalline product. Thus, factors controlling seeded growth of nanosized zeolite particles were established and the mechanism of formation, including parameters governing the formation of single or aggregated crystals, revealed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8017252