Artículo
Preparation of acetates catalyzed by boric acid and/or tungstophosphoric acid-modified zirconia obtained employing polyethylene glycols as pore-forming agents
Osiglio, Lilian
; Sathicq, Angel Gabriel
; Pizzio, Luis Rene
; Romanelli, Gustavo Pablo
; Blanco, Mirta Noemi





Fecha de publicación:
01/2017
Editorial:
Elsevier Science
Revista:
Journal of Molecular Catalysis A: Chemical
ISSN:
1381-1169
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Zirconia modified with boric acid and/or tungstophosphoric acid calcined at 320 °C were prepared, characterized and used as catalysts in the production of acetates from diverse alcohols and phenols. Polyethylene glycol (PEG) of different molecular weight (400, 2000, 6000 Da) were added as low cost pore-forming agents during zirconia synthesis using zirconyl chloride as precursor and ammonium hydroxide as precipitating agent. The zirconias were impregnated with aqueous solutions of boric acid and/or tungstophosphoric acid (TPA). The borated zirconias, zirconias modified with TPA and zirconias doped with both boron and TPA were amorphous mesoporous materials with very strong acid sites, and specific surface areas SBET of around 200, 100, and 150 m2/g, respectively. The FT-IR spectra of borated zirconias exhibited the bands of boron species, while the zirconias modified with TPA presented the characteristic bands of tungstophosphate anion, and the zirconias doped with both boron and TPA showed a degradation of the TPA anion, confirmed by 31P MAS-NMR. The borated zirconias and the zirconias modified with TPA gave excellent selectivity and yield in the 2-phenylethanol esterification with acetic acid. The use of these materials allows obtaining higher or similar results than those reported in the literature. Zirconias doped with both boron and TPA gave lower values, due to the transformation of the [PW12O40]3− Keggin anion in to the [P2W21O71]6− and [PW11O39]7− species. The reactivity towards acetylation with acetic acid of different alcohols and phenols using the best catalyst was ordered according to: primary alcohols > secondary alcohols > phenols. The reactivity difference of the alcohols and phenols was correlated with the electronic density on the oxygen atom and steric effects.
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Articulos(CINDECA)
Articulos de CENTRO DE INV EN CS.APLICADAS "DR.JORGE J.RONCO"
Articulos de CENTRO DE INV EN CS.APLICADAS "DR.JORGE J.RONCO"
Citación
Osiglio, Lilian; Sathicq, Angel Gabriel; Pizzio, Luis Rene; Romanelli, Gustavo Pablo; Blanco, Mirta Noemi; Preparation of acetates catalyzed by boric acid and/or tungstophosphoric acid-modified zirconia obtained employing polyethylene glycols as pore-forming agents; Elsevier Science; Journal of Molecular Catalysis A: Chemical; 426; 1-2017; 88-96
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