【Abstract】 The redox properties of molybdovanadoarsenic heteropolyacids having keggin structure,H x[AsV nM O 12-n O 40 ]·YH 2O(n=1～4),were studied with polarography,cyclic voltammetry and XPS.It was ascertained that three redution steps for the four heteropolyacids involved 2,2,2 electrons accompanied by the adition of 1,1,1 protons.A reduction mechanism has been proposed.The oxidation ability of these heteropolyacids increases with the increase of the substitution of vanadium.更多还原