Optimizing ionomer distribution for constructing efficient Pt/ionomer interfaces: Research on improving the...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Reducing platinum content in proton exchange membrane fuel cells (PEMFCs) is crucial for cost reduction.
• Low platinum loading increases oxygen transport resistance at the Pt-ionomer interface, causing voltage losses.

Purpose of the Study:

• To reduce local oxygen mass transfer resistance (R_O2-local) in low-platinum PEMFCs.
• To enhance the performance and durability of PEMFCs with reduced platinum loading.

Main Methods:

• Sulfur doping of carbon supports for platinum catalysts.
• Characterization of catalyst properties and performance in MEAs.
• Measurement of local oxygen mass transfer resistance (R_O2-local).

Main Results:

• Sulfur doping enhanced carbon support hydrophilicity, leading to uniform ionomer distribution.
• Reduced R_O2-local by 24.8% in sulfur-doped catalysts compared to undoped.
• Achieved effective Pt utilization of 0.098 g_Pt·kW^-1 in low Pt-loaded MEAs.

Conclusions:

• Sulfur doping is an effective strategy to mitigate performance losses in low-Pt PEMFCs.
• Improved ionomer distribution and reduced Pt poisoning contribute to enhanced catalyst performance.
• Sulfur-doped catalysts show promise for improved low-humidity adaptability and durability.