Tailoring ionomer distribution in the catalyst layer via heteroatom-functionalization toward superior PEMFC...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane fuel cells (PEMFCs) are crucial for clean energy.
• Catalyst performance is limited by ionomer distribution and transport properties.
• Platinum-cobalt (Pt3Co) alloys are promising electrocatalysts.

Purpose of the Study:

• To investigate the impact of oxygen (O), sulfur (S), and nitrogen (N) functionalization on Pt3Co/C catalysts.
• To understand how functionalization affects catalyst layer properties and fuel cell performance.
• To identify optimal functionalization strategies for enhanced PEMFC operation.

Main Methods:

• Synthesis of O-, S-, and N-functionalized Pt3Co/C catalysts.
• Characterization of catalyst morphology and composition.
• Electrochemical testing in a proton exchange membrane fuel cell setup.
• Analysis of ionomer distribution and gas/ion transport within the catalyst layer.

Main Results:

• Nitrogen functionalization significantly improved ionomer distribution within the catalyst layer.
• Oxygen and sulfur functionalization showed less impact on ionomer distribution compared to nitrogen.
• N-functionalization led to a trade-off between oxygen and hydronium ion transport.
• Optimized ionomer distribution with N-functionalization potentially enhances overall catalyst utilization.

Conclusions:

• Nitrogen functionalization is a key strategy for optimizing ionomer distribution in Pt3Co/C catalysts for PEMFCs.
• Careful control of functionalization is necessary to balance competing transport phenomena.
• Further research can leverage N-functionalization to improve PEMFC efficiency and durability.