3D Pd/Co core-shell nanoneedle arrays as a high-performance cathode catalyst layer for AAEMFCs.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Alkaline anion-exchange membrane fuel cells (AAEMFCs) are promising for clean energy.
• Developing efficient and cost-effective cathode catalysts is crucial for AAEMFC advancement.
• Current AAEMFCs often require high noble metal loadings and alkaline ionomers.

Purpose of the Study:

• To introduce a novel cathode architecture for AAEMFCs.
• To utilize vertically aligned cobalt nanoneedle arrays as an ordered support for cathode catalysts.
• To enhance AAEMFC performance while reducing noble metal (palladium) loading.

Main Methods:

• Vertically aligned Co nanoneedle arrays were synthesized on stainless steel via hydrothermal reaction.
• A palladium (Pd) layer was deposited onto the Co nanoneedles using vacuum sputter-deposition, forming Pd/Co nanoneedle arrays.
• The Pd/Co nanoneedle arrays were integrated into an alkaline anion-exchange membrane (AAEM) to create the cathode catalyst layer.

Main Results:

• The developed cathode catalyst layer achieved enhanced performance in AAEMFCs.
• Ultra-low Pd loading (33.5 μg cm⁻²) was demonstrated, significantly lower than conventional Pt loading (100 μg cm⁻²).
• The AAEMFC operated effectively without an alkaline ionomer, delivering higher power density than conventional membrane electrode assemblies (MEAs).

Conclusions:

• Vertically aligned Co nanoneedle arrays serve as an effective cathode support in AAEMFCs.
• This novel architecture enables high performance with substantially reduced palladium usage.
• The findings present a new pathway for cost-effective and efficient AAEMFC development without alkaline ionomers.