Pd-Pt bimetallic nanodendrites with high activity for oxygen reduction

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Controlling platinum (Pt) nanostructure morphology is key to improving catalytic properties and mass activity.
• The oxygen reduction reaction (ORR) is the rate-determining step in proton-exchange membrane fuel cells, necessitating efficient catalysts.

Purpose of the Study:

• To synthesize and characterize palladium-platinum (Pd-Pt) bimetallic nanodendrites.
• To evaluate the catalytic performance of these nanodendrites for the oxygen reduction reaction (ORR).

Main Methods:

• Synthesis of Pd-Pt bimetallic nanodendrites via reduction of K2PtCl4 with L-ascorbic acid in the presence of Pd nanocrystal seeds.
• Characterization of nanodendrite morphology and surface area.
• Electrocatalytic testing for ORR activity.

Main Results:

• Successfully synthesized Pd-Pt bimetallic nanodendrites with a Pd core and dense Pt branches.
• The nanodendrites exhibited large surface areas and active facets for ORR.
• Pd-Pt nanodendrites demonstrated 2.5 times higher ORR activity than state-of-the-art Pt/C and 5 times higher than Pt-black catalysts on a Pt mass basis.

Conclusions:

• Morphology control of Pt nanostructures offers significant opportunities for enhanced catalytic performance.
• Pd-Pt nanodendrites represent a promising advanced catalyst for the oxygen reduction reaction (ORR) in fuel cells.