Reaction-driven restructuring of defective PtSe₂ into ultrastable catalyst for the oxygen reduction reaction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Two-dimensional PtM dichalcogenides offer unique electronic and optoelectronic properties.
• Their potential as oxygen reduction reaction (ORR) electrocatalysts is limited by semiconducting nature and low surface area.
• Defective platinum diselenide (DEF-PtSe2) presents an opportunity for catalyst development.

Purpose of the Study:

• To develop a highly efficient and stable electrocatalyst for the oxygen reduction reaction (ORR).
• To investigate the restructuring of defective platinum diselenide (DEF-PtSe2) for enhanced catalytic activity.
• To understand the underlying mechanisms contributing to improved ORR performance.

Main Methods:

• Synthesizing defective platinum diselenide (DEF-PtSe2).
• Electrochemical cycling in an O2-saturated electrolyte to restructure the material.
• Performance evaluation via specific activity, mass activity, and stability tests.
• Quantum mechanical calculations using hybrid density functional theory (DFT).

Main Results:

• Restructured DEF-PtSe2 demonstrated 1.3x higher specific activity and 2.6x higher mass activity than commercial Pt/C.
• The catalyst maintained superior ORR performance with minimal decay even after 126,000 cycles.
• DFT calculations revealed synergistic contributions from Pt nanoparticles and apical active sites on DEF-PtSe2.

Conclusions:

• Restructured DEF-PtSe2 is a highly efficient and durable electrocatalyst for ORR.
• The study highlights the potential of PtM dichalcogenides in electrocatalysis.
• This work provides insights into designing advanced catalysts based on DEF-PtSe2.