Characterization of K-mixed V2O5 catalyst and oxidative dehydrogenation of propane on it

The structure of K containing V2O5 catalysts has been studied by XRD and spectroscopic methods. The particles of V2O5 were oriented sharply to the direction perpendicular to b axis. The spacings of (010) and (200) planes were slightly contracted by the presence of K ions. V2O5 bronze seemed to be less Raman-active. IR spectra gave the structural information of K-V2O5 at low content of K. The IR bands at 1023 and 830 cm(-1) of V2O5 shifted to 1000 and 785 cm(-1) respectively. This suggests that K ions are present at some micro space of V2O5 crystal. The K-V2O5 catalyst oriented to (010) plane exhibited high selectivity (ca. 80%) to C3H6 in the oxidation of C3H6 while the activity decreased with the O-18 by the reduction with C3H8 and reoxidation increase in K content. Oxygen ions of oriented V2O5 were exchanged with with O-18(2). Raman spectra's analysis of the catalysts exchanged with O-18 suggests that V=O species are responsible for oxidative dehydrogenation of C3H8 to C3H6. (C) 2000 Elsevier Science B.V. All rights reserved.