Hollow-Structure Pt-Ni Nanoparticle Electrocatalysts for Oxygen Reduction Reaction

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• High oxygen reduction reaction (ORR) activity and stability are crucial for electrocatalysts.
• Start-stop operation demands robust catalysts that resist degradation.

Purpose of the Study:

• To investigate hollow-structure platinum-nickel (Pt-Ni) electrocatalysts for ORR applications.
• To evaluate the activity, durability, and start-stop performance of these novel catalysts.

Main Methods:

• Synthesis of hollow-structure Pt-Ni electrocatalysts using a sacrificial SiO2 template method.
• Electrochemical characterization including Tafel and K-L plots to evaluate ORR kinetics.
• Accelerated durability testing (ADT) and start-stop durability tests.

Main Results:

• The Pt-Ni electrocatalyst demonstrated significantly higher specific activity (1.88 mA/cm2) and mass activity (0.49 A/mg) compared to commercial Pt/C.
• The catalyst exhibited superior durability during ADT.
• The Pt-Ni electrocatalyst showed good resistance to start-stop operation, with smaller drops in specific and mass activity (34.6% and 40.8%) than commercial catalysts.

Conclusions:

• Hollow-structure Pt-Ni electrocatalysts are promising alternatives to commercial Pt/C for ORR.
• These catalysts offer enhanced activity and stability, particularly for applications involving start-stop conditions.