Phase Engineering of Intermetallic PtBi

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Phase engineering of platinum-based intermetallic catalysts is a key strategy for improving direct formic acid fuel cell performance.
• Platinum-bismuth (Pt-Bi) intermetallic catalysts offer high activity and CO poisoning resistance for the formic acid oxidation reaction (FAOR).
• Conventional synthesis methods for intermetallic compounds often require high temperatures, limiting control over size and composition.

Purpose of the Study:

• To synthesize intermetallic β-PtBi2 and γ-PtBi2 two-dimensional (2D) nanoplates with controlled size and composition under mild conditions.
• To investigate the effect of different PtBi2 phases on catalytic performance for the FAOR.
• To evaluate the CO poisoning tolerance of the synthesized PtBi2 catalysts.

Main Methods:

• Synthesis of 2D intermetallic β-PtBi2 and γ-PtBi2 nanoplates using mild reaction conditions.
• Characterization of synthesized nanoplates for controlled size and composition.
• Electrocatalytic testing of nanoplates for the formic acid oxidation reaction (FAOR).
• In situ infrared absorption spectroscopy to assess CO poisoning tolerance.

Main Results:

• Successfully synthesized intermetallic β-PtBi2 and γ-PtBi2 2D nanoplates with controlled dimensions and composition under mild conditions.
• The β-PtBi2 nanoplates demonstrated a superior mass activity of 1.1 ± 0.01 A mgPt-1 for the FAOR, representing a 30-fold improvement over commercial Pt/C catalysts.
• The intermetallic PtBi2 catalysts exhibited significant tolerance to CO poisoning during the FAOR.

Conclusions:

• Mild-condition synthesis enables precise control over the phase, size, and composition of intermetallic PtBi2 nanoplates.
• The β-PtBi2 phase shows exceptional catalytic activity and stability for the FAOR, outperforming commercial catalysts.
• Intermetallic PtBi2 is a highly promising catalyst for direct formic acid fuel cells due to its enhanced activity and CO tolerance.