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Applying Dynamic Strain on Thin Oxide Films Immobilized on a Pseudoelastic Nickel-Titanium Alloy
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Electrochemically Induced Strain Evolution in Pt-Ni Alloy Nanoparticles Observed by Bragg Coherent Diffraction
Tomoya Kawaguchi1,2, Vladimir Komanicky3, Vitalii Latyshev3
1Institute for Materials Research, Tohoku University, Sendai, 9808577, Japan.
Nano Letters
|July 12, 2021
Summary
Strain in platinum-nickel alloy nanoparticles boosts oxygen reduction reaction activity. This study used Bragg coherent diffraction imaging to quantify strain, aiding the design of better electrocatalysts for fuel cells and batteries.
Area of Science:
- Materials Science
- Electrochemistry
- Nanotechnology
Background:
- Surface strain significantly impacts catalytic activity in platinum alloy nanoparticles.
- Inefficiency in the oxygen reduction reaction is a major hurdle for fuel cells and metal-air batteries.
Purpose of the Study:
- To investigate strain evolution in platinum-nickel alloy nanoparticles during electrochemical cycling.
- To correlate strain distribution with catalytic activity.
Main Methods:
- Bragg coherent diffraction imaging (BCDI) was used to obtain 3D strain maps.
- A core-shell model was applied to analyze the strain distribution within nanoparticles.
Main Results:
- Significant strain (up to 5%) was observed on platinum-rich shells due to nickel dissolution.
- Strain on the shells showed a strong correlation with catalytic activity across different alloy compositions (Pt2Ni3, Pt1Ni1, Pt3Ni2).
Conclusions:
- BCDI provides quantitative strain measurements in alloy nanoparticles during electrochemical reactions.
- Harnessing surface strain is a viable strategy for designing advanced electrocatalysts.
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