Supported Keggin type heteropolycompounds for ecofriendly reactions

New supported Keggin heteropolyacid (HPA) catalysts were prepared in order to make a contribution to the field of catalyzed acid reactions by means of ecofriendly technologies. The esterification of isoamyl alcohol and acetic acid in gaseous phase was studied using tungstophosphoric acid (TPA) suppo...

Full description

Saved in:
Bibliographic Details
Published inApplied catalysis. A, General Vol. 256; no. 1-2; pp. 125 - 139
Main Authors Pizzio, L.R, Vázquez, P.G, Cáceres, C.V, Blanco, M.N
Format Journal Article
LanguageEnglish
Published Elsevier B.V 30.12.2003
Subjects
Catalysts
Ecofriendly processes
Esterification reaction
Isoamyl acetate
Keggin heteropolyacids
New supports
Keggin heteropolyacids
Isoamyl acetate
Ecofriendly processes
Catalysts
New supports
Esterification reaction
Online AccessGet full text

Cover

More Information
Summary:New supported Keggin heteropolyacid (HPA) catalysts were prepared in order to make a contribution to the field of catalyzed acid reactions by means of ecofriendly technologies. The esterification of isoamyl alcohol and acetic acid in gaseous phase was studied using tungstophosphoric acid (TPA) supported on different carriers, silica materials, carbon and alumina. These catalysts were characterized by FT-IR, DRS, TPR and their acidity was evaluated through the isopropanol dehydration test reaction. The higher acidic catalysts prepared with silica materials led to the greatest activities due to the higher proton availability which, in turn, was related to the lower interaction and dispersion of the active species. In order to perform this acid reaction in heterogeneous liquid phase and to avoid the tungstophosphoric or molybdophosphoric acid (MPA) solubilization during reaction, functionalized silica and SiMCM-41, and polyvinyl alcohol hydrogel–polyethylenglycol (PVA-PVG) beads were used as new supports. The physical–chemical characterization of the supported catalysts by FT-IR, XRD, 31P MAS NMR and TG-DTA showed mainly undegraded primary Keggin structure. The solids exhibited low or negligible solubilization and their acidity, measured by potentiometric titration with n-butylamine, was high. The SiMCM-41 and polymeric bead-supported catalysts lead to obtain attractive activity in the isoamyl acetate synthesis through esterification reaction.
ISSN:0926-860X
1873-3875
DOI:10.1016/S0926-860X(03)00394-6