Synthesis and conductivity of undecatungsto chromoferrous heteropoly acid

The ternary undecatungsto chromoferrous heteropoly acid (HPA) H6Fe(H2O)CrW11O39·14H2O has been synthesized for the first time by the stepwise acidification and the stepwise addition of solutions of the component elements as well as ion exchanging–cooling method. The optimal proportion of the solutions of the component elements and the pH of the synthesis reaction are given. The product is characterized by chemical analysis, IR, UV, XRD and TG-DTA. The results of AC impedance measurement show that its proton conductivity is 3.89×10−3 S cm−1 at room temperature (20°C).