Preparation and Electrochemical Performance of Tungstovanadophosphoric Heteropoly Acid and Its Hybrid Materials

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• 作者：Xia Tong ; Naiqin Tian ; Wen Wu ; Weiming Zhu ; Qingyin Wu ; Fahe Cao ; Wenfu Yan ; A. B. Yaroslavtsev
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：February 21, 2013
• 年：2013
• 卷：117
• 期：7
• 页码：3258-3263
• 全文大小：319K
• 年卷期：v.117,no.7(February 21, 2013)
• ISSN：1932-7455

文摘

Tungstovanadophosphoric heteropoly acid H₆PW₉V₃O₄₀路(13.81 卤 0.13)H₂O (abbreviated as PW₉V₃) has been synthesized by the stepwise acidification and the stepwise addition of element solutions. The crystal structure was determined from single crystal X-ray diffraction. The complex crystallizes in the space group R3̅m, with a = 16.4374 (9) 脜, b = 16.4374 (9) 脜, c = 25.3866 (14) 脜, 伪 = 90掳, 尾 = 90掳, 纬 = 120掳, V = 5940.20 脜, and Z = 6. The product possesses Keggin structure, and its conductivity was 1.730 脳 10^鈥? S路cm^鈥? at 26 掳C and 75% relative humidity by electrochemical impedance spectroscopy (EIS) measurement. Two conducting systems were prepared with a mixture of as-synthesized PW₉V₃ and organic polymers [polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG)] at the weight ratio 80:20. The hybrid materials exhibit high proton conductivities with 7.110 脳 10^鈥? and 1.050 脳 10^鈥? S路cm^鈥? (PW₉V₃/PEG) at 26 掳C and 75% relative humidity, respectively. Their activation energies of proton conduction are 15.23 and 13.67 kJ路mol^鈥?, which are lower than that of pristine heteropoly acid (25.68 kJ路mol^鈥?). Their mechanisms of proton conduction are also proposed.