Degradation Mechanisms in Proton Exchange Membrane Fuel Cells

Proton exchange membrane fuel cells (PEMFCs) convert hydrogen and oxygen into electricity with water as the only by-product, offering a zero-emission alternative to combustion engines. Despite their promise, long-term operation is hampered by a range of degradation mechanisms that progressively erode performance. At the cathode, high potentials drive carbon support corrosion, leading to collapse of the pore structure, loss of hydrophobicity and detachment or agglomeration of platinum nanoparticles. Cyclic potential excursions during start-up and shut-down further accelerate carbon oxidation and provoke platinum dissolution and Ostwald ripening. The polymer electrolyte membrane itself may suffer chemical attack by radical species, resulting in pinhole formation and mechanical embrittlement. Concurrently, ionomer redistribution and water-management issues cause local drying or flooding, compounding mass-transport losses. Mechanical stresses induced by hydration–dehydration cycles and thermal fluctuations can delaminate catalyst layers and degrade gas-diffusion media. Together, these intertwined processes lead to loss of electrochemical surface area, reduced catalyst utilisation and increased internal resistance. Understanding the interplay between electrochemical, morphological and chemical degradation pathways under realistic cycling and load conditions is essential for improving PEMFC durability and enabling widespread deployment in transportation and stationary power applications.

Research from Nature Portfolio

Recent studies have examined the effect of dynamic load changes on PEMFC degradation by varying the current ramp rate across repeated drive-cycle simulations. It was found that slower ramp rates attenuate the severity of catalyst layer delamination and platinum agglomeration, reducing overall performance loss by approximately half compared with more abrupt load transitions. Electrochemical impedance spectroscopy and microscopy analyses revealed that gradual loading helps maintain the integrity of the membrane–electrode assembly by moderating local potential spikes that would otherwise accelerate carbon corrosion and platinum dissolution. These findings underscore the importance of optimised control strategies within fuel-cell systems to prolong operational lifetimes under realistic automotive duty cycles.

Degradation Mechanisms in Proton Exchange Membrane Fuel Cells publication trend

The graph below shows the total number of articles in degradation mechanisms in proton exchange membrane fuel cells across all publications each year (not limited to Nature Index journals).

Technical terms

Proton exchange membrane fuel cell (PEMFC): An electrochemical device that uses a polymer membrane to conduct protons from anode to cathode while electrons travel through an external circuit.

Carbon corrosion: Electrochemical oxidation of carbon support materials under high potential, leading to structural collapse and catalyst detachment.

Electrochemical surface area (ECSA): The active area of catalyst accessible for electrochemical reactions, typically measured via adsorption or voltammetry techniques.

Oxygen reduction reaction (ORR): The cathodic reaction in PEMFCs in which oxygen molecules are reduced to water, often the rate-limiting step.

Accelerated stress test (AST): Laboratory protocols involving cyclic potential or load variations designed to simulate years of fuel-cell operation within a shorter timeframe.

References

1. Degradation Mechanisms of Carbon Supports under Hydrogen Passivation Startup and Shutdown Process for PEFCs. Journal of The Electrochemical Society (2017).
2. A study of the influence of current ramp rate on the performance of polymer electrolyte membrane fuel cell. Scientific Reports (2022).
3. “Straw in the Clay Soil” Strategy: Anticarbon Corrosive Fluorine‐Decorated Graphene Nanoribbons@CNT Composite for Long‐Term PEMFC. Advanced Science (2024).
4. Heteroatom-Doped Carbon Supports with Enhanced Corrosion Resistance in Polymer Electrolyte Membrane Fuel Cells. Energies (2023).