Vanadyl phosphates characterization

E. C. Zampronio and H. P. Oliveira, Synthesis, spectroscopic and structural characterization of poly-o-methoxyaniline and poly-o-methylanihne intercalated into layered vanadyl phosphate. Mater. Res. Bull, 39, 1525-1538 (2004). 

It is now considered, by most groups working in this area, that vanadyl pyrophosphate (VO)2P207 is the central phase of the Vanadium Phosphate system for butane oxidation to maleic anhydride (7 ). However the local structure of the catalytic sites is still a subject of discussion since, up to now, it has not been possible to study the characteristics of the catalyst under reaction conditions. Correlations have been attempted between catalytic performances obtained at variable temperature (380-430 C) in steady state conditions and physicochemical characterization obtained at room temperature after the catalytic test, sometimes after some deactivation of the catalyst. As a consequence, this has led to some confusion as to the nature of the active phase and of the effective sites. (VO)2P207, V (IV) is mainly detected by X-Ray Diffraction. 

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