The V-O-Al catalyst was prepared by hydrothermal-fluid drying synthesis method and was tested in the dehydrogenation of isobutane to isobutene. The catalysts were characterized by means of XRD, ESR, TPR and BET. The V-O-Al catalyst, derived from hydrothermal synthesis and possessing a higher vanadia dispersion in the alumina and larger surface area, especially showed a better catalytic activity and marked stability than the supported vanadium oxide catalyst.
The ESR spectra of catalyst V_2O_5/γ-Al_2O_3 and its activity for the dehydrogenation of isobutane were investigated. On the basis of the results of the ESR spectroscopy associated with the TPR results, it is suggested that there is a strong interaction between V_2O_5 and γ-Al_2O_3 and the V 4+ species on the surface is the active center of catalyst V_2O_5/γ-Al_2O_3 for this reaction.
