Rapid oxidation of a persistent organophosphate chemical warfare agent (CWA) analogue by aqueous 15 wt% hydrogen peroxide solutions containing hetero-metal substituted Wells-Dawson polyoxometalates (POMs), [Zr (alpha(2)-P2W17O61)(2)](16-) and [Ni(alpha(2)-P2W17O61)](8-), was accomplished. A novel decontamination method was employed in which oxidation reactions were performed via direct application of aqueous POM solutions onto the CWA analogue, notably without the use of surfactants to promote POM solubility in organic media. POM facilitated reactions occurred at the interface of the aqueous decontamination solution and organic contaminant, the biphasic nature of which affords easy separation and recovery of the POM catalyst for future use. Oxidation of Demeton-S with 15 wt% hydrogen peroxide alone was slow with a reaction half-life of 40.9 min. Incorporation of Ni2+ and Zr4+ POMs increased the oxidation rate significantly and reduced the reaction half-lives to 20.5 and 2.2 min, respectively. The Ni2+ POM increased the rate of reactive species formation by decomposing hydrogen peroxide. The Zr4+ POM when dissolved in 15 wt% hydrogen peroxide resulted in a beneficial in situ structural rearrangement, generating the Zr4+ POM species [Zr(H2O)(3)(alpha(2)-P2W17O61)(6-) and the Venturello complex [(PO4{W(O)(O-2)(2)}(4)](3-)), with other tungsten peroxo species. The combination of these highly active compounds in solution increased the reaction rate 20-fold over hydrogen peroxide alone, with a half-life of 2.2 min.