A novel method of the synthesis of molybdovanadophosphoric heteropoly acid solutions

A novel eco-friendly method of the synthesis of aqueous solutions of the Keggintype Mo-V-P heteropoly acids H_3+x PV _x Mo_12−x O₄₀ (HPA-x) is proposed. At the first stage, V₂O₅ is dissolved in cooled H₂O₂ to form peroxyvanadic compounds, which spontaneously decompose to yield a H₆V₁₀O₂₈ solution. The latter is stabilized by the addition of H₃PO₄ to yield a H₉PV₁₄O₄₂ solution that is added to a boiling aqueous suspension of (H₃PO₄ + MoO₃). This suspension is gradually evaporated producing the HPA-x solution. This safe and practically wasteless method holds much promise for the preparation of HPA-x solutions with x = 2–6.