Catalytic System Based on Sub-2 nm Pt Particles and Its Extraordinary Activity and Durability for Oxygen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Platinum nanoparticles on carbon supports are crucial catalysts for the oxygen reduction reaction (ORR) in proton-exchange membrane fuel cells.
• Catalyst deactivation due to nanoparticle detachment and sintering remains a significant challenge, limiting fuel cell performance and lifespan.

Purpose of the Study:

• To develop a novel method for the *in situ* growth of highly dispersed and stable sub-2 nm platinum nanoparticles on carbon supports.
• To enhance the catalytic activity and durability of platinum catalysts for the oxygen reduction reaction (ORR).

Main Methods:

• Utilized a galvanic reaction between a platinum(II) precursor and an amorphous selenium film predeposited on a commercial carbon support.
• Investigated the role of residual selenium as an anchoring linker for platinum nanoparticles.
• Performed accelerated durability testing (20,000 cycles) to evaluate catalyst stability and performance.

Main Results:

• Successfully synthesized sub-2 nm platinum nanoparticles anchored to the carbon support via residual selenium.
• The resulting catalytic system exhibited extraordinary activity and durability for the ORR.
• Even after extensive cycling, the platinum nanoparticles remained well-dispersed and maintained over three times the mass activity of commercial Pt/C catalysts.

Conclusions:

• The *in situ* growth method using galvanic reactions and selenium as a linker effectively prevents platinum nanoparticle detachment and sintering.
• This approach offers a promising strategy for developing advanced, durable, and highly active electrocatalysts for fuel cell applications.
• The enhanced stability and activity of the platinum nanoparticles pave the way for improved proton-exchange membrane fuel cell performance.