Recent Advances in Regeneration of Aqueous Low-Vanadium Mo-V-Phosphoric Heteropoly Acid Solutions with O2

At present, the aqueous solutions of low-vanadium Mo-V-phosphoric heteropoly acids (HPA-1 and HPA-2) are widely used in various areas of catalysis owing to their oxidizing ability. It has been shown that in the presence of concentrated acetic acid the reduced solutions of these HPAs can be almost completely oxidized with oxygen at high reaction rate at a temperature below 100 degrees C and atmospheric pressure. This opens broad prospects for the development of new catalytic oxidation technologies in the presence of low-vanadium heteropoly acid solutions as reversible oxidants.