【摘要】 建立了一个新球型催化层微观结构模型,并基于此模型对质子交换膜燃料电池(PEMFC)性能进行了模拟.该模型中假设催化层由Pt/C颗粒和离子聚合物-孔混合相组成.假设Pt/C颗粒为球形结构,其直径符合正态分布,用不同直径的球来表示随机分散在电极中的Pt/C颗粒.计算了催化层内的传递和电化学反应,研究了质子和氧气及电化学反应速率在电极厚度方向上的分布,并且通过对比氧气浓度、过电位和电化学反应速率的分布、极化曲线及催化剂利用率等证明了适当的电极厚度与Pt/C颗粒粒径有利于提高电池性能.更多还原

【Abstract】 The catalyst layer in a proton-exchange-membrane fuel cell(PEMFC) was simulated based on a sphere-microstructure model that consisted of Pt/C particles and a mixed ionomer-pore phase. Pt/C particles were randomly distributed in the model and were treated as spheres with a normal distribution of their size assumed. Transport and electrochemical reactions in the model catalyst layer were calculated. The variation of oxygen level, overpotential, reaction rate, and cell current through the catalyst layer was discussed in relation to changes in electrode thickness and Pt/C particle size. The corresponding polarization curves were also analyzed. Through this analysis, optimal values for electrode thickness and particle size were achieved.更多还原