Synthesis and conductivity of substituted heteropoly acid with Dawson structure H 7[Ga(H 2O)P 2W 17O 61]·18H 2O

Abstract

A new solid high-proton conductor, H 7[Ga(H 2O)P 2W 17O 61]·18H 2O, 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 -3 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. © The Author(s) 2011.