Ternary Heterostructural Pt/CN_x/Ni as a Supercatalyst for Oxygen Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Oxygen reduction reaction (ORR) is crucial for energy conversion devices.
• Platinum-based catalysts are highly effective but expensive and prone to degradation.
• Developing stable, low-platinum catalysts with high activity is a key challenge.

Purpose of the Study:

• To engineer a novel ternary heterostructure catalyst (Pt/CNx/Ni) for enhanced oxygen reduction.
• To investigate the role of nitrogen-doped carbon (CNx) interlayer in catalyst performance and stability.
• To evaluate the activity and durability of the new catalyst against commercial standards.

Main Methods:

• Fabrication of a unique Pt/CNx/Ni ternary heterostructure.
• Characterization of the catalyst's structure and composition.
• Electrochemical testing, including cyclic voltammetry, to assess oxygen reduction activity and stability under acidic conditions.

Main Results:

• The Pt/CNx/Ni catalyst exhibits significantly enhanced specific mass activity (~780%) and specific surface activity (~490%) compared to commercial Pt/C.
• The CNx interlayer effectively mediates electron transfer and protects the nickel (Ni) nanoparticles from corrosion.
• The catalyst demonstrates exceptional stability, maintaining high mass activity (0.72 A/mgPt at 0.90 V) after 50,000 cycles, exceeding U.S. Department of Energy targets.

Conclusions:

• The engineered Pt/CNx/Ni heterostructure represents a highly active and stable supercatalyst for oxygen reduction.
• The unique structure with a CNx interlayer is key to achieving superior performance and durability.
• This low-platinum catalyst design offers a promising pathway for advancing electrochemical energy technologies.