Ex situ investigation of the proton exchange membrane chemical decomposition

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• 作者：Fang Wang ; Haolin Tang ; Mu Pan ; Daoxi Li
• 关键词：Polymer electrolyte membrane fuel cells ; Degradation mechanism ; ; none ; color ; black"" href=""/science?_ob=MathURL&_method=retrieve&_udi=B6V3F-4S80CPN-1&_mathId=mml15&_user=1067359&_cdi=5729&_rdoc=20&_acct=C0000502
• 刊名：International Journal of Hydrogen Energy
• 出版年：2008
• 出版时间：May 2008
• 年：2008
• 卷：33
• 期：9
• 页码：2283-2288
• 全文大小：495 K

文摘

The durability of Nafion^® polymer electrolyte membranes (PEMs) with potential application in PEM fuel cells has been investigated using accelerated durability tests to understand their degradation mechanism. After the attack by Fenton radicals, the e517409c632b9797a0196"" title=""Click to view the MathML source"" alt=""Click to view the MathML source"">Nafion^®111 membranes and the solution produced were collected for analysis. The existence of F ions in the solution indicated the chemical decomposition of the e58f009c37644d2037898e"" title=""Click to view the MathML source"" alt=""Click to view the MathML source"">Nafion^® membranes during radical attacks. The F^- emission rate (FER) was about a7ce8122e8c5583f4e6ac17f"">, corresponding to 0.024 wt % of F released from the membrane per hour. The NMR and FTIR spectrums demonstrated the polymer fragments mostly existed as whole side chains of the 96149d9ce1ea8eae8e63fa3244b7"" title=""Click to view the MathML source"" alt=""Click to view the MathML source"">Nafion^® membrane. This result revealed that the degradation was originated from the decomposition of polymer main chain. Furthermore, the reflectance-FTIR revealed that the degradation of the PEMs was from the decomposition of the repeating units in the polymer main chains. With the increased loss of repeating units, small bubbles with the diameter of several microns started to form in b069f6b872a9"" title=""Click to view the MathML source"" alt=""Click to view the MathML source"">Nafion^® membrane. These bubbles made the membrane vulnerable to hazards of gas crossover, which further led a catastrophic failure of the proton exchange membrane.