Lewis Acid Sites Assisted PtCu/CeO₂-C Enabling High-Performance for Oxygen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing durable and active low-platinum (Pt) nanocatalysts is crucial for advancing clean energy technologies.
• The oxygen reduction reaction (ORR) is a key process in fuel cells, requiring efficient catalysts.

Purpose of the Study:

• To develop an efficient cerium dioxide (CeO2) supported platinum-copper (PtCu) alloy catalyst (PtCu/CeO2-C) for ORR in acidic media.
• To investigate the role of CeO2 support in enhancing catalyst stability and activity.

Main Methods:

• Synthesis of PtCu/CeO2-C nanocatalyst.
• Electrochemical characterization including specific and mass activity measurements at 0.9 V.
• Theoretical studies to understand the catalytic mechanism, focusing on oxygen vacancies (VO).

Main Results:

• PtCu/CeO2-C exhibited significantly higher specific activity (9.9 times) and mass activity (6.1 times) compared to commercial Pt/C.
• The CeO2 support effectively anchored PtCu particles, preventing migration and enhancing long-term stability.
• Theoretical analysis confirmed that oxygen vacancies on CeO2 facilitate O2 adsorption/dissociation and optimize Pt electronic structure for an efficient 4-electron ORR pathway.

Conclusions:

• The rational design of supported Pt-based catalysts, utilizing materials like CeO2, is highly effective for improving ORR efficiency.
• PtCu/CeO2-C represents a promising catalyst for clean energy applications due to its superior activity and durability.
• Understanding the role of support materials and defects, such as oxygen vacancies, is key to designing next-generation electrocatalysts.