Interstitial C/N Doping Stabilizes Pd@Pt Core-Shell Electrocatalysts by Atomic-Scale Interfacial Anchoring and Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Platinum-based multimetallic catalysts offer optimized activity and reduced precious metal usage.
• Structural instability under harsh electrochemical conditions limits commercialization of these catalysts.

Purpose of the Study:

• To identify the mechanism of structural instability in core-shell nanocatalysts.
• To develop a strategy for enhancing the durability of platinum-based electrocatalysts.

Main Methods:

• Pd@Pt core-shell nanocrystals as a model system.
• Combined techniques: SFC-ICP-MS, identical-location STEM, operando XAS, and DFT calculations.
• Interstitial C/N doping at the Pd-Pt interface.

Main Results:

• Identified a pinhole-mediated dissolution mechanism involving Pd leaching and subsequent Pt destabilization.
• C/N doping at the interface created atomic-scale anchoring, increasing the kinetic barrier for metal leaching.
• C/N-doped catalysts maintained structural integrity up to 1.50 V (vs RHE), with significant reductions in Pt and Pd dissolution.

Conclusions:

• A defect-targeted strengthening strategy using interstitial doping effectively stabilizes multimetallic heterointerfaces.
• This approach is generalizable to other systems like Pd-Au and Pd-Ag.
• The findings pave the way for developing durable, low-platinum electrocatalysts for commercial applications.