H₂O₂-scavenging intermetallic Pt₅Ce/C as a highly active and durable oxygen reduction electrocatalyst.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Oxygen reduction reaction (ORR) is crucial for fuel cells.
• Catalyst stability and activity are key challenges in ORR.
• Hydrogen peroxide (H2O2) generation can degrade catalysts.

Purpose of the Study:

• To develop a novel oxygen reduction catalyst with intrinsic antioxidant properties.
• To investigate the role of subsurface cerium in enhancing catalyst performance.
• To improve the activity and durability of catalysts for the oxygen reduction reaction.

Main Methods:

• Synthesis of an intermetallic platinum-cerium/carbon (Pt5Ce/C) catalyst.
• Electrochemical characterization of the catalyst under operating conditions.
• Analysis of the catalyst's surface structure and electronic properties.

Main Results:

• The Pt5Ce/C catalyst forms a Pt-skin surface under electrochemical conditions.
• Subsurface cerium atoms electronically tune the Pt-skin, promoting H2O2 scavenging.
• The Pt5Ce/C catalyst demonstrated a two-fold faster reaction rate compared to antioxidant-coupled catalysts.

Conclusions:

• The intermetallic Pt5Ce/C catalyst possesses intrinsic antioxidant functionality.
• This novel catalyst design significantly enhances catalytic activity and durability for the oxygen reduction reaction.
• The findings offer a new strategy for designing robust electrocatalysts.