Synthesis and conductivity of substituted heteropoly acid with Dawson structure H[Ga(HO)PWO]·18HO.

A new solid high-proton conductor, H[Ga(HO)PWO]·18HO, a substituted heteropoly acid with Dawson structure, has been synthesized by the degradation/ion-exchange/freezing method. The product was characterized by potentiometric titration, chemical analysis, IR, UV, XRD and TG-DTA. Complex impedance measurements show a high conductivity (5.44×10 S/cm at 50°C), with an activation energy for proton conduction of 36.04 kJ/mol. The mechanism of proton conduction is the Vehicle mechanism. [ABSTRACT FROM AUTHOR]