Study on water uptake of proton exchange membrane by using tritiated water sorption method
Study on water uptake of proton exchange membrane by using tritiated water sorption method
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DOI：
10.1016/j.ijhydene.2005.02.006
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发表时间：
2005-08
影响因子：
7.2
通讯作者：
H. Takata;M. Nishikawa;Yusaku Arimura;T. Egawa;S. Fukada;M. Yoshitake
中科院分区：
文献类型：
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作者：
H. Takata;M. Nishikawa;Yusaku Arimura;T. Egawa;S. Fukada;M. Yoshitake
认识到水在质子交换膜（PEM）中的行为是优化质子交换膜燃料电池（PEMFC）性能的必要条件。本文认为PEM膜中除吸附水外，还存在一定量的结构水。结构水是指任何被化学吸附的水、结晶水和一些与结构紧密相连的含氢化学基团。因此，由于结构水的量不依赖于蒸汽压，所以不能用吸水法来测量结构水的量。本研究采用氚化水吸附法测量吸附量和结构水的量，其中水蒸气中的氚与结构水中的氢之间的同位素交换反应使结构水的定量成为可能。在室温下，包括结构水在内的总吸收量的观测值为0.45-0.57 （g H2O/cm3PEM）。这个数值大约是迄今为止从水吸附实验中报道的量的1.5倍。本研究还测量了氢、氧和氦通过PEM膜的渗透行为，并估计了燃料流动停止时PEMFC内氢或氧的分压变化。
It is recognized that the behavior of water in the proton exchange membrane (PEM) is to be understood to optimize the performance of the proton exchange membrane fuel cell (PEMFC). It is considered by the present authors that a certain amount of structural water exists besides adsorbed water in the film of PEM. The structural water represents any chemically adsorbed water, crystal water and some chemical groups containing hydrogen which are strongly connected with the structure. Accordingly, the amount of structural water cannot be measured by the water adsorption method because the amount of structural water does not depend on the vapor pressure. The amount of adsorption together with the amount of structural water is measured in this study by using the tritiated water sorption method where the isotope exchange reaction between tritium in water vapor and hydrogen in structural water makes it possible to quantify the structural water. The observed values for the total amount of uptake water, which includes the structural water, is 0.45–0.57 (g H2O/cm3PEM) at the room temperature. This value is about 1.5 times larger than the amount reported so far from the water adsorption experiments. The permeation behavior of hydrogen, oxygen and helium through the film of PEM is also measured in this study and change of partial pressure of hydrogen or oxygen in PEMFC at stop of the fuel flows is estimated.