Simulation of Sphere-Microstructure Model of the Catalyst Layer in a PEMFC

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.