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Three-dimensional strain dynamics govern the hysteresis in heterogeneous catalysis
Aline R Passos1, Amélie Rochet2, Luiza M Manente3
1Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970, Campinas, SP, Brazil. aline.passos@lnls.br.
Nature Communications
|September 19, 2020
Summary
Understanding catalyst strain dynamics is key for developing better catalysts. This study observed anisotropic strain in gold nanocrystals during CO oxidation, revealing how strain influences active site formation and catalytic performance.
Area of Science:
- Materials Science
- Surface Chemistry
- Nanotechnology
Background:
- Catalyst stability and efficiency are critical for industrial applications.
- Understanding nanoscale strain dynamics is essential for designing advanced catalysts.
- Operando studies are needed to observe catalysts under reaction conditions.
Purpose of the Study:
- To investigate the in situ three-dimensional strain evolution of single gold nanocrystals during catalytic CO oxidation.
- To observe nanoscale anisotropic strain dynamics and their effect on active site formation.
- To map the elastic energy landscape of single nanoparticles and correlate it with catalytic performance hysteresis.
Main Methods:
- Coherent X-ray diffractive imaging (CXDI) was used for in situ strain analysis.
- Operando conditions were employed to study the catalytic CO oxidation reaction.
- High-precision mapping of the nanoparticle elastic energy landscape was performed.
Main Results:
- Direct observation of anisotropic strain dynamics at the nanoscale.
- Identical crystallographic facets showed different strain responses, leading to preferential active site formation.
- Single nanoparticle elastic energy landscapes exhibited hysteresis dependent on heating/cooling cycles, mirroring catalytic performance hysteresis.
Conclusions:
- Anisotropic strain dynamics play a significant role in forming active sites on gold nanocrystals.
- Single-particle strain hysteresis directly correlates with macroscopic catalytic hysteresis.
- This study provides a powerful platform for investigating catalytic nanomaterials and deactivation mechanisms at the single-particle level.
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