Mechanism of Water Content on the Electrochemical Surface Area of the Catalyst Layer in the Proton Exchange Membrane Fuel Cell.
Mechanism of Water Content on the Electrochemical Surface Area of the Catalyst Layer in the Proton Exchange Membrane Fuel Cell.
复制标题
DOI：
10.1021/acs.jpclett.9b02549
复制
发表时间：
2019-10
期刊：
影响因子：
--
通讯作者：
Linhao Fan;Kangcheng Wu;Chasen Tongsh;M. Zhu;Xu Xie;K. Jiao
中科院分区：
文献类型：
--
作者：
Linhao Fan;Kangcheng Wu;Chasen Tongsh;M. Zhu;Xu Xie;K. Jiao
采用分子动力学（MD）模拟和实验相结合的方法，研究了质子交换膜燃料电池催化层电化学表面积（ECSA）含水量的变化机理。通过MD模拟，催化剂层中的水域的形态对ECSA具有强烈的影响。在低水含量下，水畴的形态是孤立的水簇，由于缺乏质子传输路径，导致ECSA较差。随着水含量的增加，水畴形态从孤立水团簇向水通道网络的转变过程中，质子的传输路径趋于快速建立，从而导致ECSA的快速增加。然而，在高水含量的ECSA略有增加，主要是由于水畴和Pt颗粒之间的接触面积的改善，而不是形成新的传输路径。此外，在低温下，水分子与Pt颗粒的更强结合导致更高的ECSA。
Combined molecular dynamics (MD) simulation and experiment are adopted to gain the mechanism of water content on the electrochemical surface area (ECSA) of the catalyst layer in a proton exchange membrane fuel cell. The morphology of water domains in the catalyst layer has a strong impact on the ECSA via MD simulation. The morphology of the water domains is isolated water clusters at low water content, resulting in the poor ECSA due to the lack of proton transport paths. The transport paths of protons tend to be quickly established with increasing water content during the transition process of the morphology of water domains from isolated water clusters to the water channel network, thereby leading to the rapid increase of the ECSA. However, the slight increase of the ECSA at high water content mainly results from the improved contact area between water domains and Pt particle instead of the formation of new transport paths. In addition, the stronger binding of water molecules and the Pt particle at low temperature results in a higher ECSA.