Synthesis of Molybdovanadophosphoric Heteropoly Acid Solutions Having Modified Composition
Applied Catalysis A: General
, E-ISSN: 1873-3875
||Homogeneous catalysts, Mo-V-phosphoric heteropoly acids, Synthesis
Boreskov Institute of Catalysis SB RAS
A new practically wasteless method of synthesis of high-vanadium Mo–V–phosphoric heteropoly acids aqueous solutions having modified composition HaPzMoyVx′Ob (HPA-x′zP) has been developed. These solutions are used as thermally stable catalysts of oxidation of organic compounds with O2. At the first stage of the synthesis, V2O5 is dissolved in the cooled H2O2 to form peroxy vanadium compounds, which spontaneously decompose to yield H6V10O28 solution. The latter is stabilized by addition of an excess of H3PO4. The prepared (H9PV14O42 + H3PO4) solution is added to a gradually evaporating suspension of (MoO3 + H3PO4) to form the HPA-x′zP solution. The catalysts based on HPA-x′zP solutions do not yield V-containing deposits up to 170 °C. Syntheses of HPA-x′zP solutions can be realized both in a lab and pilot scale.