Integrated Catalyst and Membrane Degradation Model for Proton Exchange Membrane Fuel Cells

Abstract

Proton Exchange Membrane Fuel Cells (PEMFCs) represent a promising alternative to traditional combustion engines due to their high efficiency and low emissions. Despite many advantages, their commercial viability is constrained by durability concerns, particularly in the membrane electrode assembly. Complementing experimental approaches, mathematical models offer a cost-effective way to study PEMFCs and gain insights that are challenging to obtain through experiments alone. However, current PEMFC degradation models primarily focus on isolated components or mechanisms, limiting their applicability to specific accelerated stress tests (ASTs). In this study, a PEMFC degradation model that couples both catalyst and membrane degradation is developed based on a 1D, two-phase, and non-isothermal modelling framework. The membrane sub-model incorporates membrane decomposition and the transport/adsorption of degradation products, and the catalyst sub-model addresses PtO/PtOH balance, Pt degradation, and Pt band formation. Simulations using combined AST protocols and dynamic driving cycles provide insights into the impact of operating conditions on different degradation mechanisms, revealing that catalyst degradation is the primary cause of the irreversible performance decay and a reduced lower voltage bound may be necessary for an effective combined H2/air AST protocol compared to traditional H2/N2 ASTs.

Keywords: Proton exchange membrane fuel cells, degradation model, membrane decomposition, Pt degradation, Pt band