Numerical simulation of ordered catalyst layer in cathode of proton exchange membrane fuel cells

A steady, two-dimensional numerical model was presented in order to analyze and optimize the performance of an ordered cathode catalyst layer in Proton Exchange Membrane Fuel Cells. The model equations, which account for the electron and proton transport, the oxygen diffusion in the gas pores and the electrolyte phase and the electrochemical reaction kinetics, were solved by the finite element method. The simulation results revealed that the ordered catalyst layer performance was greatly increased by improving various transport processes. It was also found that the key obstacle to mass transport was oxygen diffusion in the electrolyte, whereas electron and proton transport, oxygen diffusion in gas pores imposed no substantial impacts. The performance enhancement by decreasing the diameters of carbon supports and gas pores, or increasing the catalyst layer thickness was mainly ascribed to the higher catalyst loadings. The electrolyte film thickness played an important role in improving the performance of the ordered cathode catalyst layer.