Magnetron Sputtering Deposition Cu@Onion-like N-C as High-Performance Electrocatalysts for Oxygen Reduction Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Core-shell structures enhance the activity and stability of nonprecious metallic catalysts for the oxygen reduction reaction (ORR).
• Developing cost-effective, high-efficiency, and reproducible synthesis methods for these materials is crucial.

Purpose of the Study:

• To fabricate encapsulated copper nanoparticles with nitrogen-doped onion-like graphite nanoshells (Cu@onion-like N-C) as an efficient ORR catalyst.
• To investigate the structure-activity relationship and synergistic effects within the core-shell catalyst.

Main Methods:

• Magnetron sputtering was employed to synthesize the Cu@onion-like N-C catalyst.
• The graphite shells were grown via an in situ self-assembly process activated by the surface-catalyzed behavior of Cu nanoparticles.

Main Results:

• The optimized Cu@onion-like N-C catalyst (CuCN-650 °C) exhibited small Cu nanoparticles and few-layer nanoshells.
• It demonstrated excellent ORR electrocatalytic properties, with half-wave and onset potentials comparable to commercial Pt/C.
• The catalyst showed superior stability and methanol tolerance compared to Pt/C in alkaline electrolytes.

Conclusions:

• The synergistic effect between encapsulated Cu nanoparticles and N-doped C shells, driven by electronic charge donation and pyridinic N formation, is responsible for the enhanced ORR activity.
• Cu@onion-like N-C presents a promising nonprecious catalyst alternative for ORR applications.