Cobalt-Based Cathode Catalysts for Oxygen-Reduction Reaction in an Anion Exchange Membrane Fuel Cell

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Anion exchange membrane fuel cells (AEMFCs) are promising for clean energy conversion.
• Developing efficient and cost-effective cathode catalysts is crucial for AEMFC performance.
• Platinum-based catalysts are effective but expensive, necessitating alternatives.

Purpose of the Study:

• To synthesize and characterize a novel cobalt-nitrogen-carbon (Co-N-C) material as a cathode catalyst for AEMFCs.
• To investigate the catalytic activity and electrochemical performance of the Co-N-C catalyst for the oxygen reduction reaction (ORR).
• To compare the performance of the Co-N-C catalyst with commercial platinum catalysts.

Main Methods:

• Synthesis of cobalt-chelating polyimine (Co-PIM) via Schiff reaction.
• Preparation of Co-N-C catalyst through two-stage calcination.
• Characterization using FTIR, XRD, Raman spectroscopy, SEM, TEM, and BET analysis.
• Electrochemical evaluation including linear sweeping voltammetry (LSV) in KOH(aq).

Main Results:

• The Co-N-C catalyst exhibited a single-atom CoNx structure.
• Remarkable ORR activity was observed at 0.8 V with an onset potential of 1.19-1.37 V.
• The catalyst demonstrated a high power density (361 mW cm⁻²) comparable to commercial Pt/C (284 mW cm⁻²).

Conclusions:

• The novel Co-N-C catalyst shows significant potential as an efficient and cost-effective alternative to platinum for AEMFC cathodes.
• The single-atom CoNx structure is key to the catalyst's high ORR activity.
• Further research into Co-N-C catalysts could advance AEMFC technology.