Caracterização textural e estrutural de V 2O 5/TiO 2 obtidos via sol-gel: Comparação entre secagem convencional e supercrítica
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FapUNIFESP (SciELO)
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Resumo
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
Idioma
Português
Citação
Quimica Nova, v. 25, n. 2, p. 209-213, 2002.
