Boosting the Durability of High-Pt-Content Fuel Cell Cathode Catalysts Through TaO_x Decorating

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Durability of carbon-supported platinum catalysts (Pt/C) is crucial for proton exchange membrane fuel cells (PEMFCs).
• High-platinum-content catalysts face significant durability challenges.
• Oxygen reduction reaction (ORR) catalysts require enhanced stability for practical applications.

Purpose of the Study:

• To develop a TaOx decorating strategy to improve the durability of high-Pt-content Pt/C catalysts.
• To investigate the effect of annealing temperature on TaOx formation and catalyst stability.
• To evaluate the performance enhancement of decorated catalysts under accelerated durability testing.

Main Methods:

• Introducing reducible Ta2O5 nanoparticles into carbon supports.
• Depositing platinum nanoparticles onto the modified support.
• High-temperature H2 annealing to form amorphous TaOx on Pt nanoparticles.
• Controlled annealing temperature to optimize TaOx distribution and Pt-TaOx interaction.

Main Results:

• A relatively continuous TaOx distribution on Pt nanoparticle surfaces was achieved by controlling annealing temperature.
• Maximized interaction between Pt and TaOx enhanced electrochemical stability.
• The decorated high-Pt-content catalyst showed only 30% electrochemical surface area loss, 35% mass activity loss, and 22 mV voltage loss at 0.8 A cm-2 after accelerated durability testing.

Conclusions:

• The TaOx decorating strategy effectively boosts the durability of high-Pt-content Pt/C catalysts.
• Optimized TaOx distribution is key to enhancing catalyst stability and performance in PEMFCs.
• This approach offers a promising solution for developing durable and high-performance fuel cell catalysts.