PECULIARITIES OF THE EFFECT OF VANADIUM IONS ON MOLYBDENA DEVELOPMENTUNDER PREREACTION CONDITIONS

The dynamics of phase transformations and the state of individual ions in the vanadium-molybdenum system were studied by in situ X-ray diffr action, IR spectroscopy, EPR, DTA, TGA, and mass-spectroscopy. An acti ve catalytic system comprised of three defect phases based on molybden a is developed during olefin oxidation. A modifying vanadium additive that stabilizes the active component (hexagonal MoO3 phase) makes an e ssential impact on the activity of the catalyst formed. Changes of val ence state in the anion-cation sublattice are accompanied by a rearran gement of the catalyst component's crystal structure under conditions of the catalytic reaction.