Preparation and conductibility of solid high-proton conductor molybdovanadogermanic heteropoly acid

The molybdovanadogermanic heteropoly acid H5GeMo11VO40·24H2O was prepared for the first time by the stepwise acidification and the stepwise addition of solutions 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), potentiometric titration, IR, UV, 51V NMR, powder X-ray diffraction, and thermal analysis. The results of ac impedance measurement show that its proton conductivity is 2.03 × 10−4 s·cm−1 at 18°C and the activation energy for proton conduction is 39.74 kJ/mol.