Publication: Caracterização textural e estrutural de V 2O 5/TiO 2 obtidos via sol-gel: Comparação entre secagem convencional e supercrítica
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Abstract
This work describes a modified sol-gel method for the preparation of V 2O 5/TiO 2 catalysts. The samples have been characterized by N 2 adsorption at 77K, x-ray diffractometry (XRD) and Fourier Transform Infrared (FT-IR). The surface area increases with the vanadia loading from 24 m 2 g -1, for pure TiO 2, to 87 m 2 g -1 for 9wt.% of V 2O 5. The rutile form is predominant for pure TiO 2 but became enriched with anatase phase when vanadia loading is increased. No crystalline V 2O 5 phase was observed in the catalysts diffractograms. Two species of surface vanadium observed by FT-IR spectroscopy a monomeric vanadyl and polymeric vanadates, the vanadyl/vanadate ratio remains practically constant.
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Catalyst, Sol-gel, Vanadium and titanium oxide, monomer, nitrogen, polymer, titanium dioxide, vanadic acid, vanadium derivative, vanadium pentoxide, vanadyl derivative, adsorption, catalyst, crystallization, gel, infrared spectroscopy, intermethod comparison, methodology, phase transition, species differentiation, surface property, X ray diffraction
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Portuguese
Citation
Quimica Nova, v. 25, n. 2, p. 209-213, 2002.