Prijatelj, M., Kregar, A., Kravos, A. and Katrašnik, T. (2025), Modeling Core-Shell Pt–Co Catalyst Degradation in Fuel Cells Using a Continuum Approach. ChemElectroChem 2500055.
This paper presents a new numerical model for bimetallic (BM) alloyed core–shell catalyst degradation, providing a deeper understanding of the interplay between shell thickness-dependent specific activity (SA), resistance to electrochemical degradation, and mitigation of poisoning effects caused by alloying metal dissolution. Whereas state-of-the-art BM degradation models have been limited to a discrete description of a small set of core–shell particles, the proposed framework overcomes these restrictions by applying a continuity-equation-based approach that describes the rate of change of particle radii.
The model enables, for the first time, the simulation of a full 2D distribution of core and shell nanoparticles, capturing not only the impact of surface area loss but also the critical variation of SA as a function of shell thickness. This dual assessment allows for a more realistic quantification of catalytic activity loss during operation. Furthermore, the framework is extended to propose a degradation mitigation strategy by mixing BM and pure platinum catalysts. This approach limits alloying metal dissolution while minimizing the loss of electrochemical activity, thus providing a pathway towards more durable PEMFC catalyst layers.
Highlights
- Develops a continuity-equation-based model for BM core–shell catalyst degradation.
- Simulates the evolution of a full 2D particle size distribution instead of discrete cases.
- Evaluates activity loss from both surface area reduction and shell thickness-dependent SA.
- Demonstrates a hybrid catalyst strategy combining BM and Pt to reduce dissolution.
- Provides a predictive framework for designing durable PEMFC catalyst layers in heavy-duty applications.