Sub-3 nm Intermetallic Ordered Pt₃In Clusters for Oxygen Reduction Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High cost and limited stability of platinum-based catalysts hinder industrial oxygen reduction reaction (ORR) applications.
• Developing efficient and durable ORR catalysts is crucial for advancing technologies like fuel cells.

Purpose of the Study:

• To synthesize a novel, cost-effective, and stable platinum-indium (Pt3In) catalyst for oxygen reduction reactions (ORR).
• To evaluate the catalytic activity and durability of the synthesized Pt3In/C catalyst compared to commercial platinum on carbon (Pt/C).

Main Methods:

• Facile, large-scale synthesis of sub-3-nm ordered Pt3In clusters on commercial carbon black.
• Electrochemical characterization, including mass activity and specific area activity measurements at 0.9 V vs reversible hydrogen electrode.
• Accelerated electrochemical durability testing (20,000 cycles).
• Density-functional-theory (DFT) calculations to understand ORR energetic favorability.

Main Results:

• The synthesized Pt3In/C catalyst demonstrated significantly enhanced mass activity (4.1x) and specific area activity (2.7x) compared to commercial Pt/C.
• The Pt3In/C catalyst exhibited remarkable stability, with negligible activity and structural decay after extensive durability testing.
• DFT calculations confirmed that the ordered Pt3In structure is energetically more favorable for ORR.

Conclusions:

• Facile synthesis of ordered Pt3In clusters on carbon black offers a promising, cost-effective, and stable alternative to commercial Pt/C catalysts for ORR.
• The enhanced performance and durability of Pt3In/C are attributed to its ordered structure and favorable electronic properties for ORR.