Synergistic Electronic Effects in Pt-Based Bifunctional Electrocatalysts through Fe-Co Dual Sites Engineering

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Platinum-based catalysts are crucial for fuel cells but suffer from high cost and poor durability.
• Oxygen Reduction Reaction (ORR) and Alcohol Oxidation Reactions (AOR) are key processes limited by current catalyst performance.

Purpose of the Study:

• To design and synthesize a cost-effective and durable bifunctional catalyst for efficient ORR and AOR.
• To investigate the synergistic effects of atomically dispersed Fe-N4 and Co-N4 dual sites with platinum nanoparticles.

Main Methods:

• Synthesis of platinum nanoparticles anchored on nitrogen-doped carbon support with engineered Fe-N4 and Co-N4 dual sites (Pt/FeCoNC).
• Electrochemical characterization of the catalyst for ORR and AOR performance in acidic media.
• Durability testing to assess catalyst stability over extended operational cycles.

Main Results:

• Pt/FeCoNC exhibited a half-wave potential of 0.90 V vs RHE for acidic ORR, with 5.6x higher mass activity than commercial Pt/C.
• The catalyst retained ~60% of its initial mass activity after 30,000 cycles, significantly outperforming Pt/C (~33% retention).
• Exceptional AOR activity was observed, with mass activities for methanol and ethanol oxidation over 3x greater than Pt/C.

Conclusions:

• Dual-atom site engineering with Fe-N4 and Co-N4 sites effectively enhances platinum catalyst activity and durability.
• Synergistic interactions between Pt and bimetallic sites modulate electronic properties, weakening intermediate adsorption and improving stability.
• Pt/FeCoNC represents a promising bifunctional catalyst for advanced energy conversion applications.