Direct Integration of Strained-Pt Catalysts into Proton-Exchange-Membrane Fuel Cells with Atomic Layer Deposition

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Platinum catalysts are crucial for the oxygen reduction reaction (ORR) in hydrogen fuel cells.
• Achieving high catalytic activity and durability remains a challenge.
• Lattice strain is an emerging strategy to enhance catalyst performance.

Purpose of the Study:

• To design and fabricate lattice-strained platinum catalysts using atomic layer deposition.
• To investigate the impact of lattice strain on ORR catalytic activity.
• To explore strategies for improving high-current-density (HCD) performance in fuel cells.

Main Methods:

• Synthesis of platinum shell/soluble core nanoparticles via atomic layer deposition.
• Removal of the soluble core to induce lattice strain.
• Electrochemical evaluation of catalyst performance in half-cell and full-cell configurations.
• Optimization of nanoparticle geometry and ionomer/carbon interactions.

Main Results:

• Fabrication of lattice-strained platinum catalysts with enhanced ORR activity.
• Achieved mass activity close to 0.8 A mg_Pt^-1 @0.9 V iR-free in membrane electrode assemblies.
• Demonstrated that high ORR activity does not always translate to high performance in the HCD region.

Conclusions:

• Lattice strain is an effective approach to enhance ORR catalysis.
• Further optimization is needed to improve HCD performance for practical fuel cell applications.
• Future research should focus on HCD performance to enable high-power-density hydrogen fuel cells.