Artículos de revistas
Synthesis and characterization of niobium modified montmorillonite and its use in the acid-catalyzed synthesis of beta-hydroxyethers
Registro en:
Applied Catalysis A-general. Elsevier Science Bv, v. 311, n. 199, n. 203, 2006.
0926-860X
WOS:000240380600024
10.1016/j.apcata.2006.06.019
Autor
Gallo, JMR
Teixeira, S
Schuchardt, U
Institución
Resumen
Montmorillonite K10 was ion-exchanged with polyhydroxyniobium obtained from niobium pentachloride by hydrolysis. This modified clay was characterized by X-ray diffraction, thermogravimetric analysis, inductively coupled plasma emission (ICP-OES) and nitrogen adsorption/ desorption. The obtained material was used in the alcoholysis of epoxidized methyl oleate with methanol, leading to beta-hydroxyethers. The reaction with ion-exchanged montmorillonite (Nb-Mont) was four times faster at 60 degrees C and three times faster under reflux than the one using the original clay. This proves the increase of Bronsted acidity when polyhydroxyniobium is present. The Nb-Mont was also calcined at 300, 500 and 900 degrees C to obtain the Nb-pillared montmorillonite. However, the activity of the calcined Nb-Mont decreased with increasing calcination temperature. On the other hand, calcined montmorillonite maintained its basal distance, even after treatment at 900 degrees C. (C) 2006 Elsevier B.V. All rights reserved. 311 199 203