Documents disponibles écrits par cet auteur

Synthesis, characterization, and catalytic activity of phosphorus modified H - ZSM - 5 catalysts in selective ethanol dehydration / Kanaparthi Ramesh in Industrial & engineering chemistry research, Vol. 49 N° 9 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4080-4090 Titre : Synthesis, characterization, and catalytic activity of phosphorus modified H - ZSM - 5 catalysts in selective ethanol dehydration Type de document : texte imprimé Auteurs : Kanaparthi Ramesh, Auteur ; Jie Chang, Auteur ; Yi-Fan Han, Auteur Année de publication : 2010 Article en page(s) : pp. 4080-4090 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dehydration  Catalyst  Catalyst  activity Résumé : Phosphorus (P) modified H-ZSM-5 catalysts were prepared by wet impregnation method by varying P loadings from 0 to 7.43 wt % using phosphoric acid (H3PO4) as the P source. The catalysts were tested for ethanol dehydration in the temperature range of 523—723 K. The P-modified catalysts were found to be highly active and selective toward ethylene at 673 K and atmospheric pressure. In addition, the P-modified catalysts were found to be extremely stable more than 200 h without any sign of deactivation. However, the selectivity was found to be strongly dependent on several factors such as P content, reaction temperature, and space velocity (WHSV). The P-modified ZSM-5 catalysts were also found to be highly active for the dehydration of aqueous ethanol solutions (10 wt %) showing very high ethylene selectivity (above 98%) at significantly lower temperature 623 K. The catalysts were thoroughly characterized using various methods, including N2 physisorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric differential thermal analysis (TG-DTA), 1H, 27Al, and 31P magic angle spinning nuclear magnetic resonance (MAS NMR), and amonia temperature programmed desorption (NH3-TPD). 27Al MAS NMR spectra suggest that P addition facilitate the breaking of Si―O―Al bond that lead to a partial dealumination. NH3-TPD results indicate that total acidity as well as density of high strength acid sites were decreased with P loading. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22732897 [article] Synthesis, characterization, and catalytic activity of phosphorus modified H - ZSM - 5 catalysts in selective ethanol dehydration [texte imprimé] / Kanaparthi Ramesh, Auteur ; Jie Chang, Auteur ; Yi-Fan Han, Auteur . - 2010 . - pp. 4080-4090. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4080-4090 Mots-clés : Dehydration  Catalyst  Catalyst  activity Résumé : Phosphorus (P) modified H-ZSM-5 catalysts were prepared by wet impregnation method by varying P loadings from 0 to 7.43 wt % using phosphoric acid (H3PO4) as the P source. The catalysts were tested for ethanol dehydration in the temperature range of 523—723 K. The P-modified catalysts were found to be highly active and selective toward ethylene at 673 K and atmospheric pressure. In addition, the P-modified catalysts were found to be extremely stable more than 200 h without any sign of deactivation. However, the selectivity was found to be strongly dependent on several factors such as P content, reaction temperature, and space velocity (WHSV). The P-modified ZSM-5 catalysts were also found to be highly active for the dehydration of aqueous ethanol solutions (10 wt %) showing very high ethylene selectivity (above 98%) at significantly lower temperature 623 K. The catalysts were thoroughly characterized using various methods, including N2 physisorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric differential thermal analysis (TG-DTA), 1H, 27Al, and 31P magic angle spinning nuclear magnetic resonance (MAS NMR), and amonia temperature programmed desorption (NH3-TPD). 27Al MAS NMR spectra suggest that P addition facilitate the breaking of Si―O―Al bond that lead to a partial dealumination. NH3-TPD results indicate that total acidity as well as density of high strength acid sites were decreased with P loading. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=22732897