Molecular Dynamics Study of Oxygen Diffusivity in Catalyst Layer
Molecular Dynamics Study of Oxygen Diffusivity in Catalyst Layer
复制标题
催化剂层氧扩散率的分子动力学研究
DOI：
10.1149/09208.0023ecst
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Tokumasu Takashi
中科院分区：
文献类型：
--
作者：
Nakauchi Masataka;Mabuchi Takuya;Yoshimoto Yuta;Kaneko Toshihiro;Kinefuchi Ikuya;Takeuchi Hideki;Tokumasu Takashi
采用分子动力学模拟方法研究了催化剂层中离聚物表面氧扩散系数的变化规律。分析了化学发光中由离聚物膜构成的狭缝孔中的氧扩散现象。氧分子在离聚物膜上的停留时间随着水含量的增加而增加。停留时间与表面距离之间的关系表明氧分子在表面上运动的方向性。表面距离的概率密度函数（PDF）显示了随着含水量的增加，表面氧分子的向前运动。这一结果表明，结合表面扩散的努森扩散是必要的，以考虑在CL中的氧扩散的准确分析。
Molecular dynamics (MD) simulations have been performed to investigate the oxygen diffusivity incorporating surface diffusion on the ionomer surface in catalyst layer (CL). Oxygen diffusion phenomena in slit pore composed of the ionomer film modeled as a nanopore in CL was analyzed. The residence time of oxygen molecules on the ionomer film increases as the water content increases. The relationship between the residence time and surface distance suggests the directivity of the motion of oxygen molecules on the surface. The probability density functions (PDFs) of the surface distance show the forward motion of oxygen molecules on the surface with increasing the water content. This result indicates that the Knudsen diffusion incorporating the surface diffusion is necessary to consider for an accurate analysis of oxygen diffusion in CL.