Wang Chao, Cheng Xiaojing, Lu Jiabin, Shen Shuiyun, Yan Xiaohui, Yin Jiewei, Wei Guanghua, Zhang Junliang
Institute of Fuel Cells, School of Mechanical Engineering, and ‡SJTU-ParisTech Elite Institute of Technology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai, 200240, China.
J Phys Chem Lett. 2017 Dec 7;8(23):5848-5852. doi: 10.1021/acs.jpclett.7b02580. Epub 2017 Nov 17.
Remarkable progress has been made in reducing the cathodic Pt loading of PEMFCs; however, a huge performance loss appears at high current densities, indicating the existence of a large oxygen transport resistance associated with the ultralow Pt loading catalyst layer. To reduce the Pt loading without sacrificing cell performance, it is essential to illuminate the oxygen transport mechanism in the catalyst layer. Toward this goal, an experimental approach to measure the oxygen transport resistance in catalyst layers is proposed and realized for the first time in this study. The measuring approach involves a dual-layer catalyst layer design, which consists of a dummy catalyst layer and a practical catalyst layer, followed by changing the thickness of dummy layer to respectively quantify the local and bulk resistances via limiting current measurements combined with linear extrapolation. The experimental results clearly reveal that the local resistance dominates the total resistance in the catalyst layer.
在降低质子交换膜燃料电池（PEMFCs）的阴极铂载量方面已经取得了显著进展；然而，在高电流密度下会出现巨大的性能损失，这表明与超低铂载量催化剂层相关的氧传输阻力很大。为了在不牺牲电池性能的情况下降低铂载量，阐明催化剂层中的氧传输机制至关重要。为了实现这一目标，本研究首次提出并实现了一种测量催化剂层中氧传输阻力的实验方法。该测量方法涉及双层催化剂层设计，它由一个虚拟催化剂层和一个实际催化剂层组成，然后通过改变虚拟层的厚度，结合线性外推法通过极限电流测量分别量化局部电阻和整体电阻。实验结果清楚地表明，局部电阻在催化剂层的总电阻中占主导地位。
