Nitrogenated Graphene Quantum Dot-Derived Copper Single-Atom Catalyst for Oxygen Reduction Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Fuel cells are promising sustainable energy technologies but are limited by the high cost of platinum group metal (PGM) catalysts for the oxygen reduction reaction (ORR).
• Developing cost-effective, non-PGM alternatives for ORR catalysis is crucial for widespread fuel cell adoption.

Purpose of the Study:

• To report copper-based single-atom catalysts (Cu-SACs) as efficient and economical non-PGM alternatives for ORR.
• To develop a practical synthetic strategy for producing high-density, atomically dispersed Cu active sites.

Main Methods:

• Synthesis of Cu-SACs via pyrolysis of pyrene-derived amine-terminated graphene quantum dots (GQDs) with nitrogen and metal precursors.
• Characterization using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and high-resolution scanning transmission electron microscopy (HR-STEM).
• Electrochemical measurements to evaluate ORR activity and reaction pathway.

Main Results:

• The synthesis successfully stabilized isolated copper atoms within a porous carbon matrix through copper-nitrogen (Cu-N) coordination.
• Characterization confirmed the atomic dispersion of Cu active sites.
• Electrochemical tests showed excellent ORR activity, predominantly via a four-electron pathway.

Conclusions:

• Copper-based single-atom catalysts are viable, cost-effective alternatives to PGMs for ORR.
• The developed synthetic method offers a practical route to economically viable, non-precious metal catalysts for fuel cells.