V(2)O(5)/TiO(2) catalytic xerogels raman and EPR studies

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorRodella, C. B.
dc.creatorFranco, RWA
dc.creatorMagon, C. J.
dc.creatorDonoso, J. P.
dc.creatorNunes, LAO
dc.creatorSaeki, Margarida Juri
dc.creatorAegerter, M. A.
dc.creatorSargentelli, V
dc.creatorFlorentino, A. O.
dc.date2014-05-20T13:53:21Z
dc.date2016-10-25T17:03:57Z
dc.date2014-05-20T13:53:21Z
dc.date2016-10-25T17:03:57Z
dc.date2002-08-01
dc.date.accessioned2017-04-05T21:08:38Z
dc.date.available2017-04-05T21:08:38Z
dc.identifierJournal of Sol-gel Science and Technology. Dordrecht: Springer, v. 25, n. 1, p. 83-88, 2002.
dc.identifier0928-0707
dc.identifierhttp://hdl.handle.net/11449/19040
dc.identifierhttp://acervodigital.unesp.br/handle/11449/19040
dc.identifier10.1023/A:1016049212766
dc.identifierWOS:000176462200010
dc.identifierhttp://dx.doi.org/10.1023/A:1016049212766
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/865029
dc.descriptionRaman spectroscopy and Electron Paramagnetic Resonance (EPR) studies were performed on a series of V(2)O(5)/TiO(2) catalysts prepared by a modified sol-gel method in order to identify the vanadium species. Two species of surface vanadium were identified by Raman measurements, monomeric vanadyls and polymeric vanadates. Monomeric vanadyls are characterized by a narrow Raman band at 1030 cm(-1) and polymeric vanadates by two broad bands in the region from 900 to 960 cm(-1) and 770 to 850 cm(-1). The Raman spectra do not exhibit characteristic peaks of crystalline V(2)O(5). These results are in agreement with those of X-ray Diffractometry (XRD) and Fourier Transform Infrared (FT-IR) previously reported (C.B. Rodella et al., J. Sol-Gel Sci. Techn., submitted). At least three families of V(4+) ions were identified by EPR investigations. The analysis of the EPR spectra suggests that isolated V(4+) ions are located in sites with octahedral symmetry substituting for Ti(4+) ions in the rutile structure. Magnetically interacting V(4+) ions are also present as pairs or clusters giving rise to a broad and structureless EPR line. At higher concentration of V(2)O(5), a partial oxidation of V(4+) to V(5+) is apparent from the EPR results.
dc.languageeng
dc.publisherSpringer
dc.relationJournal of Sol-Gel Science and Technology
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectcatalyst
dc.subjectvanadium and titanium oxides
dc.subjectsol-gel
dc.subjectcharacterization
dc.titleV(2)O(5)/TiO(2) catalytic xerogels raman and EPR studies
dc.typeOtro


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