Preparation and conductivity of the Keggin-type trivanadium-substituted tungstosilicic acid H7SiW9V3O40 • 9H2O

A proton conductor solid electrolyte tri-vanadium-substituted tungstosilicic acid H7SiW9V3O40 center dot 9H(2)O with Keggin structure was prepared by the stepwise acidification and the stepwise addition of element solutions. The product is characterized by Infrared (IR) spectroscopy, UV spectrum and X-ray powder diffraction (XRD). Its proton conductivity has been measured by the electrochemical impedance spectroscopy (EIS) in the temperature region 18-58 degrees C and 50% relative humidity. The conductivity increases from 2.05 x 10(-3) S cm(-1) at 18 degrees C to 8.11 x 10(-3) S cm(-1) at 58 degrees C, with an activation energy of 26.69 kJ mol(-1) for proton conduction. The conductive mechanism is Vehicle mechanism. (C) 2013 Elsevier B.V. All rights reserved.