Nanosized Proton Conductor Array with High Specific Surface Area Improves Fuel Cell Performance at Low Pt Loading.

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Ordered catalyst layers using micro-/nanostructured arrays improve fuel cell performance and reduce catalyst loading.
• Existing ordered Nafion arrays have limited proton transfer channels and catalyst loading area due to larger pillar sizes.

Purpose of the Study:

• To prepare an ordered Nafion array with significantly smaller pillar diameters (40 nm) for enhanced fuel cell applications.
• To investigate the impact of nanosized Nafion arrays on proton conductivity, catalyst loading, and overall fuel cell performance.

Main Methods:

• Optimization of Nafion solvent, thermal annealing temperature, and stripping mode from an alumina oxide template.
• Fabrication of a 40 nm diameter ordered Nafion array (D40) with high pillar density (2.7 × 10^10 pillars/cm^2).

Main Results:

• The D40 array exhibits a high specific area (51.5 cm^2/cm^2), increasing catalyst loading area and improving interface contact.
• Achieved peak power densities of 1.47 W/cm^2 (anode) and 1.29 W/cm^2 (cathode), 3.3x and 2.9x higher than without the array, respectively.
• Reduced platinum catalyst loading to 17.6 μg/cm^2 (anode) and 61.0 μg/cm^2 (cathode).

Conclusions:

• Nanosized Nafion arrays (40 nm pillars) significantly enhance fuel cell performance and enable low platinum catalyst loading.
• The developed D40 array offers a scalable approach for designing advanced catalyst layers for fuel cells, water electrolysis, and electrosynthesis.