Nitride stabilized PtNi core-shell nanocatalyst for high oxygen reduction activity.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient and stable catalysts for the oxygen reduction reaction (ORR) is crucial for energy conversion technologies.
• Low platinum content catalysts are desirable to reduce costs while maintaining high performance.

Purpose of the Study:

• To synthesize novel platinum-nickel nitride (PtNiN) core-shell catalysts with low platinum content.
• To investigate the activity and stability of these catalysts for the oxygen reduction reaction (ORR).
• To understand the role of the nickel nitride core in enhancing catalyst performance.

Main Methods:

• Synthesis of PtNiN core-shell nanoparticles via nitriding nickel nanoparticles and subsequent encapsulation with a thin platinum shell (2-4 monolayers).
• Experimental characterization of catalyst structure and composition.
• Density functional theory (DFT) calculations to elucidate the catalytic mechanism and structure-property relationships.

Main Results:

• Successfully synthesized PtNiN core-shell catalysts with a low platinum shell and inexpensive nickel nitride core.
• Demonstrated high activity and stability for the oxygen reduction reaction (ORR).
• DFT calculations confirmed the bifunctional effect of the nitride, enhancing both core-shell formation and platinum shell performance through geometric and electronic effects.

Conclusions:

• PtNiN core-shell catalysts represent a promising low-platinum alternative for ORR applications.
• The nickel nitride core plays a critical role in improving catalyst performance.
• This approach enables the design of various transition metal nitride-based core-shell nanoparticles for diverse energy conversion applications.