Unlocking Low-Temperature Ordering of Supported Pt-Based Intermetallic Compounds via Binary Salt-Matrix Strategy

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Structurally ordered platinum-based intermetallic compounds (IMCs) are essential for high-performance fuel cells.
• Synthesizing these ordered IMCs at low temperatures is challenging due to kinetic barriers in atomic diffusion.

Purpose of the Study:

• To develop a low-temperature synthesis strategy for ordered Pt-based IMCs.
• To overcome the difficulties in achieving the disorder-to-order phase transition of catalysts.

Main Methods:

• Utilized a binary salt matrix (KCl-Na2HPO4) to facilitate the phase transition of carbon-supported Pt3Co catalysts.
• Investigated the role of in-situ generated Na4P2O7 in the salt matrix for surface oxide removal and atomic rearrangement.
• Employed a flexible confinement environment provided by the salt matrix to control nanoparticle growth.

Main Results:

• Achieved a low-temperature disorder-to-order phase transition of carbon-supported Pt3Co catalysts.
• The resulting catalyst with an ordered Pt3Co core and Pt shell showed a peak power density of 1.4 W cm-2.
• The catalyst maintained 85% of its peak power density after 30,000 cycles in accelerated durability tests (ADT).

Conclusions:

• The binary salt matrix strategy enables efficient low-temperature synthesis of ordered Pt-based IMCs.
• This method significantly improves catalyst performance and durability for fuel cell applications.
• Provides a promising approach for large-scale production of advanced catalysts.