Topographical and compositional engineering of core-shell Ni@Pt ORR electro-catalysts

Area of Science:

• Materials Science
• Nanotechnology
• Electrochemistry

Background:

• Complex nanoparticle geometries and compositions enhance catalytic properties.
• Alloy nanoparticles (NPs) offer tunable electronic and structural characteristics for catalysis.

Purpose of the Study:

• To synthesize binary platinum-nickel (PtNi) alloy nanoparticles (NPs) using a co-thermolytic approach.
• To optimize synthesis variables for improved catalytic performance and durability.
• To investigate the structure-property relationships of PtNi NPs.

Main Methods:

• Co-thermolytic synthesis of binary PtNi NPs.
• Morphological characterization using scanning transmission electron microscopy (STEM).
• Electrocatalytic activity evaluation using a rotating disc electrode (RDE) in 0.1 M HClO4.

Main Results:

• Synthesized PtNi NPs with diverse morphologies, including spherical and concave cuboidal core-shell structures.
• Achieved an approximately 11-fold improvement in electrocatalytic activity compared to commercial Pt/C catalysts.
• Demonstrated excellent durability, retaining electrochemical surface area after 5000 cycles due to a protective Pt shell.

Conclusions:

• The co-thermolytic approach yields high-quality Ni@Pt NPs with superior electro-catalytic activity and durability.
• Concave cuboidal PtNi NPs exhibit enhanced stability, attributed to a thick Pt shell limiting Ni dissolution.
• This synthetic strategy offers a promising route for developing advanced electrocatalysts.