CoN₃ embedded graphene, a potential catalyst for the oxygen reduction reaction from a theoretical perspective

Area of Science:

• Materials Science
• Electrochemistry
• Theoretical Chemistry

Background:

• Non-precious metal catalysts are crucial for efficient fuel cells.
• Oxygen Reduction Reaction (ORR) is a key process in fuel cells.
• Cobalt nitride (CoN3) embedded graphene is a potential ORR catalyst.

Purpose of the Study:

• To investigate the structural stability of CoN3 embedded graphene.
• To elucidate the ORR mechanism of CoN3 embedded graphene in acidic media.
• To compare its catalytic activity with pure platinum.

Main Methods:

• Theoretical calculations were employed.
• Thermodynamic stability was assessed.
• Kinetic pathways and energy barriers for ORR were analyzed.

Main Results:

• CoN3 embedded graphene demonstrates excellent thermodynamic stability.
• The most favorable ORR pathway is a four-electron process, specifically OOH hydrogenation.
• The energy barrier for the rate-determining step (0.38 eV) is significantly lower than that of pure Pt (~0.80 eV).
• The predicted working potential is 0.4 V.
• Lower Tafel slopes compared to Pt indicate superior catalytic performance.

Conclusions:

• CoN3 embedded graphene is a thermodynamically stable material.
• It facilitates a highly efficient four-electron ORR pathway.
• Its lower energy barrier and Tafel slope suggest it is a promising, cost-effective alternative to platinum for ORR electrocatalysis in fuel cells.