A new solid high-proton conductor,H7[Ga(H2O)P2W17O61].18H2O,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℃),with an activation energy for proton conduction of 36.04 kJ/mol.The mechanism of proton conduction is the Vehicle mechanism.
The ruthenium-substituted polyoxometallic acid H6 [Ru(H2O)FeW 11O39 ]·18H2O was synthesized by stepwise acidification and stepwise addition of solutions of the component elements, and an ion-exchange-cooling method. The product was characterized using inductively coupled plasma spectrometry (ICP), Infrared Spectroscopy (IR), Ultraviolet Spectroscopy (UV), and X-ray diffraction (XRD). The results show that this complex has the Keggin structure. The determination of the thermal stability and proton conductivity of this polyoxometallic acid was carried out by a thermogravimetric-differential thermal analysis (TG-DTA) and electrochemical impedance spectroscopy (EIS).
Undecatungstocobaltoruthenic polyoxometallic acid H7[Ru(H2O)CoW11O39] 22H2O was synthesized by the stepwise acidification and the stepwise addition of solutions of the component elements as well as the ion ex changing-cooling method. The optimal proportion of the component compound and the pH of the synthesis reaction were given. The product was characterized by means of inductively coupled plasma(ICP), IR, UV and thermal analy sis. The IR and UV results indicate that H7[Ru(H2O)CoW11O39] 22H2O possesses the Keggin structure. The results of AC impedance measurement show that its proton conductivity is 2.30×10-3 S/cm at room temperature(295 K) and a relative humidity of 75%.
XU Sheng-xian1,2, WU Qing-yin2 and YAN Wen-fu3 1. School of Chemistry and Chemical Engineering, Jiangxi Science & Technology Normal University, Nanchang 330013, P. R. China
