Synthesis and conductivity of undecatungstozircogallic heteropoly acid

The undecatungstozircogallic heteropoly acid (HPA) H-5[Ga(H2O)ZrW11O39].14H(2)O was synthesized for the first time by the stepwise acidification and the stepwise addition of solution of the component elements. The optimal proportion of the component compounds and the pH of the synthesis reaction are given. The product was characterized by means of inductively coupled plasma (ICP), IR, UV, X-ray diffraction and thermal analysis. The results of AC impedance measurement show that its proton conductivity is 8.76 x 10(-4) S cm(-1) at room temperature (16 degreesC) and the activation energy for proton conduction is 21.20 kJ mol(-1). (C) 2003 Published by Elsevier B.V.