Unveiling the Origin of Morphological Instability in Topologically Complex Electrocatalytic Nanostructures
Yawei Li1,2, James L Hart3,4, Ramchandra Gawas2
1School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
Journal of the American Chemical Society
|September 6, 2025
Summary
Electrochemical conditions drive nanoparticle coarsening via dissolution/redeposition and rapid surface diffusion of atoms. This study reveals new mechanisms for catalyst degradation at room temperature.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Coarsening in metals typically involves thermally driven processes like diffusion.
- Nanometer-sized catalysts show unexpected coarsening during potential cycling at room temperature, defying thermal explanations.
- Existing models do not account for electrochemically induced mass transport in catalysts.
Purpose of the Study:
- To investigate the mechanisms behind room-temperature electrochemical coarsening in nanometer-sized catalysts.
- To elucidate the role of electrochemical conditions in catalyst morphological evolution.
- To identify novel mass transport pathways in electrocatalysts.
Main Methods:
- Coupled in situ experimental observations.
- Atomistic kinetic Monte Carlo (kMC) simulations.
- Analysis of electrochemical conditions (electrolyte, potential, scan rate).
Main Results:
- Demonstrated electrochemical coarsening driven by two concurrent atomistic mechanisms.
- Identified dissolution/redeposition during reduction of oxidized species as a key driver.
- Revealed rapid surface diffusion of undercoordinated atoms contributing to coarsening.
Conclusions:
- Electrochemical conditions, not just temperature, significantly influence catalyst coarsening.
- The study uncovers fundamental mechanisms of electrochemically induced degradation in nanostructured catalysts.
- Findings provide insights for designing more stable and durable electrocatalysts.
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