Data di Pubblicazione:
2013
Abstract:
WO3/ZrO2 systems were prepared by sol–gel technique using different procedures for the solvent extrac-
tion: evaporation in vacuum at room temperature (xerogel) and extraction in supercritical conditions
(aerogel). Two reactions of industrial interest were investigated under mild conditions: (i) acylation of
veratrole with acetic anhydride; (ii) acylation of anisole with benzoic anhydride. Several techniques were
employed in order to study the influence of the synthetic parameters on texture and catalytic activity: N 2
physisorption, Fourier transformed-infrared spectroscopy, X-ray photoelectron spectroscopy, tempera-
ture programmed reduction and temperature programmed oxidation analyses. The solvent extraction
strongly influences metal reducibility, surface area, pores organisation, W/Zr surface density and metallic
interactions. The aerogel sample shows the best catalytic results for both conversion and yield. The super-
critical extraction plays a central role especially in the recycling: by proper air activation, the aerogel
sample attains the complete restoration of the catalytic activity even after three runs.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
Sol–gel process; Acylation; Tungsten; Zirconium
Elenco autori:
Michela Signoretto; Elena Ghedini; Federica Menegazzo; Giuseppina Cerrato; Valentina Crocellà; Claudia Letizia Bianchi
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