Favorable Core/Shell Interface within Co₂P/Pt Nanorods for Oxygen Reduction Electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Core/shell nanostructures with nonprecious metal cores and platinum (Pt) ultrathin shells are promising for oxygen reduction reaction (ORR) catalysis.
• Enhancing Pt efficiency relies on core/shell interfacial strain and ligand effects, but real catalyst interactions are complex.
• Oversimplified interpretations of 3D interfaces hinder catalyst development.

Purpose of the Study:

• To investigate the impact of specific interfaces in Co2P/Pt core/shell structures on ORR catalysis.
• To develop a method for selectively controlling interface formation in nanorods for optimized catalytic activity.
• To demonstrate a generalizable strategy for creating ultralow-loading precious-metal catalysts.

Main Methods:

• Density functional theory (DFT) calculations to analyze Co2P/Pt interfaces and their effect on Pt energetics for ORR.
• Seed-mediated synthesis approach to fabricate Co2P/Pt core/shell nanorods (NRs).
• Characterization of nanorod interfaces to confirm selective expression of desired facets.

Main Results:

• DFT calculations revealed that the Co2P(001)/Pt(111) interface significantly improves ORR energetics, while Co2P(010)/Pt(111) is detrimental.
• The developed synthesis method selectively produced Co2P/Pt NRs with the beneficial Co2P(001)/Pt(111) interface on side facets, minimizing the detrimental interface.
• The resulting Co2P/Pt NRs exhibited superior ORR catalytic efficiency in acidic media compared to benchmark catalysts.

Conclusions:

• Selective control over core/shell interfaces in nanostructures is crucial for optimizing catalytic performance.
• The 1D Co2P/Pt core/shell nanorod architecture represents a novel approach for efficient ORR catalysis.
• This strategy offers a pathway for developing highly efficient, ultralow-loading precious-metal catalysts for ORR and other electrochemical reactions.