Description
The emergence of 4th generation x-ray light sources offers an unparalleled opportunity for conducting in situ and operando studies of nanoparticle structures in complex environments, especially in the field of energy materials. Gaining insights into the dynamic strain behavior of catalysts is critical for developing cost-effective, efficient, and long-lasting catalytic systems. In this talk, I will demonstrate how Bragg coherent x-ray imaging (BCDI) [1] enables three-dimensional (3D) nanoscale imaging of strain, defect dynamics, and re-faceting processes within nanoparticles during catalytic reactions.
For instance, we successfully mapped the 3D lattice displacements and strain distribution of a platinum (Pt) nanoparticle under electrochemical conditions [2] and during CO oxidation [3,4]. More recently, we achieved sub-second time resolution during operando chemical reactions, detecting oscillatory strain changes with a 6.4-second periodicity, directly associated with site-specific CO adsorption during oxidation [5], with a benchmark resolution of 0.25 seconds.
Additionally, I will present our latest findings on the core-shell transition in NiFe catalysts during annealing [6], discuss the potential of measuring particles as small as 20 nm [7], demonstrate high-energy imaging of embedded materials [8] using BCDI and show how charge-integrating detectors can improve the spatial and temporal resolutions of BCDI [9].
We acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme under grant agreement CARINE No. 818823.
REFERENCES
[1] I. Robinson and R. Harder, Coherent X-ray diffraction imaging of strain at the nanoscale, Nat. Mater. 8, 291 (2009).
[2] C. Atlan et al., Imaging the strain evolution of a platinum nanoparticle under electrochemical control, Nat. Mater. 22, 6 (2023).
[3] J. Carnis et al., Twin boundary migration in an individual platinum nanocrystal during catalytic CO oxidation, Nat. Commun. 12, 5385 (2021).
[4] M. Dupraz et al., Imaging the facet surface strain state of supported multi-faceted Pt nanoparticles during reaction, Nat. Commun. 13, 1 (2022).
[5] M. Grimes et al., Capturing Catalyst Strain Dynamics during Operando CO Oxidation, ACS Nano 18, 19608 (2024).
[6] C. Chatelier et al., Unveiling Core–Shell Structure Formation in a Ni3Fe Nanoparticle with In Situ Multi-Bragg Coherent Diffraction Imaging, ACS Nano 18, 13517 (2024).
[7] M.-I. Richard et al., Bragg coherent diffraction imaging of single 20 nm Pt particles at the ID01-EBS beamline of ESRF, J. Appl. Crystallogr. 55, 621 (2022).
[8] M.-I. Richard et al., Taking Bragg Coherent Diffraction Imaging to Higher Energies at Fourth Generation Synchrotrons: Nanoscale Characterization, ACS Appl. Nano Mater. (2023).
[9] M. Grimes et al., Bragg coherent diffraction imaging with the CITIUS charge-integrating detector, J. Appl. Crystallogr. 56, 1032 (2023).
