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.