Phase-Rearrangement-Induced Atomic Replacement toward Customizing Noble-Metal Intermetallics

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Noble-metal intermetallics show promise for catalysis but face challenges in synthesis due to favored symmetric growth and metal redox potential differences.
• Existing methods struggle to create complex, structurally controlled intermetallic nanoarchitectures.

Purpose of the Study:

• To develop a novel synthesis strategy for creating structurally controlled noble-metal intermetallic nanoarchitectures.
• To demonstrate a morphology-preserved atomic replacement method in noble-metal chalcogenides.
• To investigate the catalytic performance of the synthesized intermetallic materials.

Main Methods:

• Utilized palladium-tellurium (Pd-Te) hexagonal nanoplates as parent templates.
• Induced a phase-rearrangement followed by atomic replacement of Te by Bi atoms.
• Characterized the resulting palladium-bismuth (Pd-Bi) nanoarchitectures using various techniques.
• Evaluated the catalytic activity for the oxygen reduction reaction (ORR).

Main Results:

• Successfully synthesized morphology-preserved, tunable Pd-Bi intermetallic nanoarchitectures via phase-rearrangement-induced atomic replacement.
• Demonstrated the generalizability of the method for various dimensions and other Pd-Bi compositions (Pd-Sb, Pd-Pb, Pd-Sn).
• Hexagonal phase PdBi exhibited superior ORR activity, stability, and methanol tolerance compared to other catalysts.

Conclusions:

• The phase-rearrangement-induced atomic replacement strategy offers a versatile route to inaccessible intermetallic nanoarchitectures.
• This method overcomes limitations of traditional synthesis, enabling precise control over composition, phase, and interfaces.
• The synthesized Pd-Bi intermetallics, particularly hexagonal PdBi, show significant potential for advanced catalytic applications.