INVESTIGADORES
PIZZIO Luis Rene
artículos
Título:
Phenol tetrahydropyranylation catalyzed by supported heteropolyacids with Keggin structure
Autor/es:
G. ROMANELLI,; P. VÁZQUEZ,; L. PIZZIO,; N. QUARANTA,; J. AUTINO,; M. BLANCO,; C. CÁCERES.
Revista:
APPLIED CATALYSIS A-GENERAL
Editorial:
Elsevier
Referencias:
Lugar: Amsterdam; Año: 2004 vol. 261 p. 163 - 170
ISSN:
0926-860X
Resumen:
The catalytic behavior of molybdophosphoric or tungstophosphoric acids supported on different silica-aluminas, obtained by solgel
method, in a hydroxyl protection reaction, phenol tetrahydropyranylation, was studied. Different techniques were used to synthesize the
supports. In one of them, commercial alumina was added to a tetraethyl orthosilicate (TEOS) solution and then this was hydrolyzed. In the
other preparations, TEOS and aluminum tri-sec-butoxide were hydrolyzed, simultaneously or with TEOS prehydrolysis. The catalysts were
prepared by incipient wetness impregnation and, after their leaching with toluene, different thermal treatments were applied. The specific
surface area of the solids was measured, and the nature of the Keggin heteropolyacid species present in the catalysts was characterized by
diffuse reflectance spectroscopy and X-ray diffraction. In addition, their acidic properties were evaluated by potentiometric titration with
n-butylamine. The acetal yield was strongly dependent on the catalyst properties, mainly their acidic characteristics which, in turn, depended
on the support synthesis. Moreover, the decrease of the catalyst water content through treatment up to 250 .C led to higher yields, due to the
presence of water in the reaction medium favors the hydrolysis of the acetal.-butylamine. The acetal yield was strongly dependent on the catalyst properties, mainly their acidic characteristics which, in turn, depended
on the support synthesis. Moreover, the decrease of the catalyst water content through treatment up to 250 .C led to higher yields, due to the
presence of water in the reaction medium favors the hydrolysis of the acetal..C led to higher yields, due to the
presence of water in the reaction medium favors the hydrolysis of the acetal.