Recent progress on MN₄ macrocycle-derived oxygen reduction reaction electrocatalysts for polymer electrolyte fuel...

Area of Science:

• Electrochemistry and Materials Science
• Focus on catalysis for energy conversion technologies

Background:

• Fuel cells offer emission-free energy conversion, crucial for transportation and power generation.
• High cost and scarcity of platinum-group metal catalysts limit fuel cell commercialization.
• Development of efficient, low-cost non-precious metal electrocatalysts is a key research area.

Purpose of the Study:

• To review recent advancements in MN4 macrocycle-derived single-atom catalysts (SACs) for oxygen reduction reactions (ORR).
• To evaluate the performance and stability of these SACs in proton exchange membrane fuel cells (PEMFCs) and anion exchange membrane fuel cells (AEMFCs).
• To discuss factors influencing the fuel cell performance of transition-metal macrocyclic complexes as cathode catalysts.

Main Methods:

• Literature review of recent reports on MN4 macrocycle-derived ORR electrocatalysts.
• Analysis of structural integrity and active sites of single-atom catalysts.
• Evaluation of electrocatalytic activity, durability, and stability in fuel cell applications.

Main Results:

• Transition metal MN4 macrocycle-based SACs exhibit excellent electrocatalytic performance for ORR.
• The structural integrity of active centers in these SACs contributes to superior activity and durability.
• Review highlights viability in energy applications, alongside critical discussion of stability challenges.

Conclusions:

• MN4 macrocycle-derived SACs are promising alternatives to precious metal catalysts for fuel cells.
• Further research is needed to address stability issues for widespread commercialization.
• These catalysts hold significant potential for advancing efficient and sustainable energy conversion.