Reducing Irreversible Performance Losses via a Graphene Oxide Buffer Layer for Proton-Exchange Membrane Fuel Cells

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Proton-exchange membrane fuel cells (PEMFCs) are promising clean energy technologies.
• Alloy catalysts in PEMFCs suffer from performance degradation due to metal dissolution.
• Developing durable and stable catalysts is critical for widespread PEMFC adoption.

Purpose of the Study:

• To investigate the use of a graphene oxide (GO) buffer layer to enhance the durability of alloy catalysts in PEMFCs.
• To mitigate the irreversible performance degradation caused by the dissolution of Pt-M (M = Co, Ni, etc.) metals.
• To analyze the impact of the GO buffer layer on fuel cell performance, stability, and resistance to poisoning.

Main Methods:

• Fabrication of membrane electrode assemblies (MEAs) with a trace layer of graphene oxide (GO) film inserted between the proton-exchange membrane (PEM) and the alloy catalyst layer.
• Electrochemical evaluation of MEAs under dynamic load cycle durability testing, including shutdown and JRC-based recovery protocols.
• Characterization of current density distribution and accessible mass transport resistance within the MEAs.
• Assessment of the anti-poisoning and stability performance during accelerated stress tests.

Main Results:

• The incorporation of a GO buffer layer (specifically GO-1 μg/cm²) resulted in higher initial performance and improved stability of the alloy catalysts.
• The GO buffer layer facilitated a more homogeneous current density distribution across the membrane electrode assembly.
• A low accessible mass transport resistance was observed in MEAs utilizing the GO buffer layer.
• The GO buffer layer demonstrated significant anti-poisoning capabilities and enhanced stability during accelerated stress testing due to its ion sieving effect.

Conclusions:

• A graphene oxide buffer layer effectively mitigates the dissolution of alloy catalyst metals, thereby enhancing PEMFC durability.
• The GO buffer layer improves initial performance, stability, and mass transport properties of the membrane electrode assembly.
• The ion sieving effect of the GO layer is key to its anti-poisoning and long-term stability benefits in fuel cells.