Atomic resolution imaging of polyhedral PtPd core-shell nanoparticles by Cs-corrected STEM.

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Bimetallic nanoparticles offer unique properties compared to monometallic ones.
• Platinum-palladium (PtPd) nanoparticles are promising for catalysis in fuel cells and oxidation reactions.
• High cost of platinum necessitates the development of highly efficient, small-scale catalysts.

Purpose of the Study:

• To synthesize and characterize sub-20 nm polyhedral PtPd core-shell nanoparticles.
• To investigate the atomic-level structure and morphology of these nanoparticles.
• To identify novel structures and understand their implications for catalysis.

Main Methods:

• Synthesis of polyhedral PtPd core-shell nanoparticles.
• Characterization using Cs-corrected scanning transmission electron microscopy (Cs-STEM).
• Atomic-resolution imaging and structural analysis.

Main Results:

• Successfully synthesized PtPd core-shell nanoparticles under 20 nm.
• Atomic-level imaging revealed detailed structural information.
• Identified three main polyhedral morphologies: octahedral, decahedral, and triangular plates.
• Discovered novel decahedral PtPd core-shell nanoparticles.

Conclusions:

• PtPd core-shell nanoparticles can be synthesized with controlled polyhedral morphologies.
• Cs-corrected STEM provides unprecedented atomic-level structural insights.
• The identified morphologies, especially decahedral ones, offer new avenues for catalyst design and application.