Local gas transport limitation attributed to the ionomer thin-film in the catalyst layer is a major deterrent to widespread commercialization of polymer-electrolyte fuel cells. So far functionality and limitations of these thin-films have been assumed identical in the anode and cathode. In this study, Nafion ionomer thin-films on platinum(Pt) support were exposed to H₂ and air as model schemes, mimicking anode and cathode catalyst layers. Findings indicate decreased swelling, increased densification of ionomer matrix, and increased humidity-induced aging rates in reducing environment, compared to oxidizing and inert environments. Observed phenomenon could be related to underlying Pt-gas interaction dictating Pt-ionomer behavior. Presented results could have significant implications about the disparate behavior of ionomer thin-film in anode and cathode catalyst layers.

归因于催化剂层中的离聚物薄膜的局部气体传输限制是聚合物电解质燃料电池的广泛商业化的主要阻碍。迄今为止，已经假定这些薄膜的功能和局限性在阳极和阴极中是相同的。在这项研究中，铂（Pt）载体上的Nafion离聚物薄膜暴露于H ₂和空气作为模型方案，模仿阳极和阴极催化剂层。研究结果表明，与氧化性和惰性环境相比，在还原性环境中溶胀度降低，离聚物基质的致密化增加以及湿度引起的老化速率增加。观察到的现象可能与指示Pt离聚物行为的潜在Pt气体相互作用有关。提出的结果可能会对离聚物薄膜在阳极和阴极催化剂层中的不同行为产生重大影响。