Numerical simulation of the ordered catalyst layer in cathode of proton exchange membrane fuel cells
Numerical simulation of the ordered catalyst layer in cathode of proton exchange membrane fuel cells
复制标题
DOI：
10.1016/j.elecom.2005.09.022
复制
发表时间：
2005-12
影响因子：
5.4
通讯作者：
C. Du;Xinqun Cheng;T. Yang;Geping Yin;Peng-fei Shi
中科院分区：
文献类型：
--
作者：
C. Du;Xinqun Cheng;T. Yang;Geping Yin;Peng-fei Shi
为分析质子交换膜燃料电池有序阴极催化层的性能，建立了基于圆柱形电极结构的稳态一维数值模型。模型方程考虑了氧还原反应、质子迁移、氧在圆柱形电解液和气孔中的扩散以及氧在气体/电解液界面上的分布的Tafel动力学。模拟结果表明，有序催化层比常规催化层具有更好的性能，这是因为有序催化层的传质性能得到了改善，整个催化层的电化学反应速率更加均匀。给出了氧在气相和电解液中的扩散系数以及质子电导率的影响。气相中氧扩散的限制将催化层的活性区域推向催化层/气体扩散界面。质子迁移的限制将催化层的活性区域限制在膜/催化层界面。由于氧在电解液膜中扩散的限制，活性区域在整个有序催化剂层中保持了均匀的分布。
A steady-state, one-dimensional numerical model based on cylindrical electrode structure is presented to analyze the performance of the ordered cathode catalyst layer in Proton Exchange Membrane Fuel Cells. The model equations account for the Tafel kinetics of oxygen reduction reaction, proton migration, oxygen diffusion in the cylindrical electrolyte and the gas pores, oxygen distribution at the gas/electrolyte interface. The simulation results reveal that ordered catalyst layers have better performance than conventional catalyst layers due to the improvements of mass transport and the uniformity of the electrochemical reaction rate across the whole width of the catalyst layer. The influences of oxygen diffusivity in gas phase and electrolyte, and the proton conductivity have been shown. The limitation by oxygen diffusion in gas phase drives the active region of the catalyst layer to the catalyst layer/gas diffuser interface. The limitation by proton migration confines the active region of the catalyst layer to the membrane/catalyst layer interface. The limitation due to oxygen diffusion in electrolyte film maintains the uniform distribution of the active region throughout the ordered catalyst layer.