Enhanced operational performance of PEM fuel cells with Porous-Carbon catalyst support: A multiscale modeling approach

Replacing the conventional catalyst support of Pt/C for proton exchange membrane fuel cells (PEMFC) by meso-porous carbon is considered highly promising in improving the catalyst usage and the cell performance. How-ever, ambiguity on the mechanism of such performance enhancement hinders further optimization and imple-mentation of the porous carbon supports. Herein, we propose a unified agglomerate model for PEMFC catalyst layers with different carbon supports, valid for both normal-working and cold-start conditions, and utilizing minimal phenomenological parameters. Parametric study regarding key material properties reveals that typical porous carbon supports such as Ketjenblack enables easier cold start but slightly deteriorates the nominal working cell performance. Using sensitivity analysis, five carbon property variables have been identified as most significantly affecting the overall cell performance. Fine-tuning the carbon radius and the platinum fraction inside the micropores of Ketjenblack is found pivotal for maximizing the catalyst layer effectiveness.

Automated summary

Replacing conventional catalyst support with meso-porous carbon in PEMFC can improve catalyst usage and cell performance. However, the mechanism for this enhancement is not fully understood, hindering further optimization. This study proposes a unified agglomerate model for catalyst layers with different carbon supports, applicable for normal and cold-start conditions. Parametric study shows that Ketjenblack as a porous carbon support enables easier cold start but slightly decreases nominal cell performance, and fine-tuning its properties is crucial for maximizing catalyst layer effectiveness.