Description
Mass particle compression is a synthetic approach that can lead to the formation of either oligocrystals or nanoparticles exhibiting unconventional crystallographic orientations, which are different from the typical [111] direction observed in platinum. This process sometimes results in the emergence of vicinal surfaces (Figure 1a). In addition, some particles may contain lattice dislocations (Figure 1b). These structural features are known to enhance catalytic activity by introducing strain fields and generating active sites at the nanoscale.
In this study, we use multi-reflection Bragg coherent diffraction imaging (m-BCDI) [1–4] to fully characterize the internal structure of platinum (Pt) particles, focusing particularly on those displaying vicinal surfaces or lattice dislocations. By measuring several Bragg reflections on the same crystal (Figure 1), we reconstructed the complete three-dimensional strain, rotation and stress tensors within individual particles. The experiments were performed at the ID01 beamline of the European Synchrotron Radiation Facility (ESRF), leveraging the capabilities of the fourth-generation synchrotron source, which offers enhanced brightness and coherence. These features allowed us to monitor the structural evolution of platinum nanoparticles in real time under catalytic conditions. We followed the development of strain, lattice deformation, and defect dynamics during both thermal treatment and operando CO oxidation. These findings provide critical insights into the structure–reactivity relationships in nanostructured catalysts and underscore the capabilities of multi-BCDI for probing functional materials at the nanoscale.
This research was supported by the European Research Council (ERC) under the Horizon 2020 research and innovation program, grant agreement CARINE N0. 818823.
2020 research and innovation program, grant agreement CARINE N0. 818823.
References
[1] M. A. Pfeifer, G. J. Williams, I. A. Vartanyants, R. Harder, and I. K. Robinson, Three-Dimensional Mapping of a Deformation Field inside a Nanocrystal, Nature 442, 63 (2006).
[2] I. Robinson and R. Harder, Coherent X-Ray Diffraction Imaging of Strain at the Nanoscale, Nat. Mater. 8, 291 (2009).
[3] M. C. Newton, S. J. Leake, R. Harder, and I. K. Robinson, Three-Dimensional Imaging of Strain in a Single ZnO Nanorod, Nat. Mater. 9, 120 (2010).
[4] F. Hofmann, N. W. Phillips, S. Das, P. Karamched, G. M. Hughes, J. O. Douglas, W. Cha, and W. Liu, Nanoscale Imaging of the Full Strain Tensor of Specific Dislocations Extracted from a Bulk Sample, Phys. Rev. Mater. 4, 013801 (2020).
