阴极催化层铂载量对低温启动过程的影响

To investigate the effect of cathode Pt loading on the gas transport and reaction processes, this paper establishes a one-dimensional multiphase non-isothermal non-steady-state cold start model for proton exchange membrane fuel cells. The model is coupled with an electrochemical reaction kinetic model that accounts for the mass transfer resistance of oxygen in the multi-components of the catalyst layer. Additionally, the model considers the water transport, phase change, electrochemical reaction, electro-osmotic drag and heat transfer process. The effects of Pt loading of cathode catalyst layer on the change of performance, water content, ice volume fraction and temperature are evaluated. The results show that excessively low Pt loading hinders the cold start, while excessively high Pt loading is not conducive to improved performance. A Pt loading of 0. 1 mg/cm2 is found to be optimal. A time effect is observed during the transportation of oxygen from the catalyst layer pores to the Pt surface. As the Pt loading increases, the initial formation of ice in the cathode catalyst layer is delayed, and the ice formation rate decreases. Higher Pt loading leads to smaller gradients in membrane water content distribution across both the anode and cathode catalyst layers.