Formation of phase composition of oxidic vanadium-molybdenum system during thermal decomposition of ammonium paramolybdate and metavanadate

X-ray method was used to study the formation of the phase composition of oxide vanadium-molybdenum system upon thermal decomposition of ammonium paramolybdate and metavanadate depending on the components ratio, temperature and their calcination medium. The formation of equilibrium phases in the system under study proceeds via a number of intermediate thermally unstable oxide vanadium-molybdenum compounds (ammonium-containing and nonstoichiometric). The formation of nonstoichiometric vanadium-molybdenum is accounted for by the partial reduction of V5+ ions and occurs as a result of the crystallographic shift