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Updated: Jun 9, 2025
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On the Preparation and Testing of Fuel Cell Catalysts Using the Thin Film Rotating Disk Electrode Method
Published on: March 16, 2018
21.9K
Correlating Catalyst Growth with Liquid Water Distribution in Polymer Electrolyte Fuel Cells
Preetam Sharma1, Douglas Aaron1, Pierre Boillat2
1Electrochemical Energy Storage and Conversion Laboratory, Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37919, USA.
Small (Weinheim an Der Bergstrasse, Germany)
|October 25, 2024
Summary
Liquid water accumulation under flow field lands in polymer electrolyte fuel cells (PEFCs) accelerates platinum catalyst degradation. Optimizing flow field design is crucial for improving fuel cell durability and performance.
Area of Science:
- Materials Science
- Electrochemistry
- Chemical Engineering
Background:
- Polymer electrolyte fuel cells (PEFCs) are crucial for clean energy, but catalyst degradation limits their durability.
- Understanding catalyst degradation mechanisms is vital for advancing fuel cell technology.
Purpose of the Study:
- To investigate the impact of liquid water distribution on platinum (Pt) catalyst degradation in PEFCs.
- To correlate liquid water accumulation patterns with heterogeneous Pt particle size distribution after accelerated stress tests (ASTs).
Main Methods:
- Utilized accelerated stress tests (ASTs) on membrane electrode assemblies (MEAs) in varied cathode environments (N2 and air).
- Employed high-resolution neutron imaging to map liquid water distribution.
- Used synchrotron micro-X-ray diffraction (micro-XRD) to analyze Pt particle size distribution.
Main Results:
- Liquid water preferentially accumulates in diffusion media, particularly under flow field lands, due to thermal resistance differences.
- Aged MEAs showed increased water retention, linked to enhanced diffusion media hydrophilicity.
- Significant heterogeneity in Pt particle size was observed, correlating with areas of high liquid water accumulation.
Conclusions:
- Flow field design critically influences liquid water distribution and subsequent catalyst degradation.
- Preferential water accumulation under flow field lands exacerbates Pt catalyst degradation.
- Innovative strategies targeting water management are needed to enhance PEFC durability and performance.
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