“…The dashed plane represents the location of the cross-section. We observe a mean surface compressive to tensile strain swap (from −7.83 × 10 −5 to 1.40 × 10 −5 ) upon flowing the CO/O 2 gas mixture on the gold nanocrystal surface, in agreement with Suzana et al 12 . Fig.…”
Section: Resultssupporting
confidence: 92%
“…In situ Bragg coherent diffraction imaging (BraggCDI) recently demonstrated the possibility to obtain 3D strain maps and defects dynamic information 16 , 17 . It has been successfully employed to reveal in situ nanocrystals deformations, bulk and surface strain dynamics, localisation of active sites under operating conditions 12 , 18 – 22 . In our previous work 12 , we revealed by using in situ BraggCDI, the dynamic faceting of 120 nm gold nanoparticles supported on TiO 2 during the catalytic reaction of CO oxidation and the formation of nanotwin defective network to accommodate the strain built up under reaction conditions.…”
Section: Introductionmentioning
confidence: 99%
“…While X-ray diffraction provides average information 3 , atomic resolution is achieved using aberration-corrected transmission electron microscopy (AC-TEM) such as the work of Walsh et al 10 showing local strain variations due to the nanoparticle-support interface. Under reaction conditions, the nanoparticle structure can present dynamic restructuration, faceting process [11][12][13][14] , requiring in situ and operando imaging tools 15 . Although the development of environmental TEM enables to image catalysts under reactive conditions, as demonstrated by Vendelbo et al 11 by in situ TEM following the oscillatory behaviour of Pt nanoparticles during CO oxidation reaction, three-dimensional strain information is lacking.…”
Understanding catalysts strain dynamic behaviours is crucial for the development of cost-effective, efficient, stable and long-lasting catalysts. Here, we reveal in situ three-dimensional strain evolution of single gold nanocrystals during a catalytic CO oxidation reaction under operando conditions with coherent X-ray diffractive imaging. We report direct observation of anisotropic strain dynamics at the nanoscale, where identically crystallographically-oriented facets are qualitatively differently affected by strain leading to preferential active sites formation. Interestingly, the single nanoparticle elastic energy landscape, which we map with attojoule precision, depends on heating versus cooling cycles. The hysteresis observed at the single particle level is following the normal/inverse hysteresis loops of the catalytic performances. This approach opens a powerful avenue for studying, at the single particle level, catalytic nanomaterials and deactivation processes under operando conditions that will enable profound insights into nanoscale catalytic mechanisms.
“…The dashed plane represents the location of the cross-section. We observe a mean surface compressive to tensile strain swap (from −7.83 × 10 −5 to 1.40 × 10 −5 ) upon flowing the CO/O 2 gas mixture on the gold nanocrystal surface, in agreement with Suzana et al 12 . Fig.…”
Section: Resultssupporting
confidence: 92%
“…In situ Bragg coherent diffraction imaging (BraggCDI) recently demonstrated the possibility to obtain 3D strain maps and defects dynamic information 16 , 17 . It has been successfully employed to reveal in situ nanocrystals deformations, bulk and surface strain dynamics, localisation of active sites under operating conditions 12 , 18 – 22 . In our previous work 12 , we revealed by using in situ BraggCDI, the dynamic faceting of 120 nm gold nanoparticles supported on TiO 2 during the catalytic reaction of CO oxidation and the formation of nanotwin defective network to accommodate the strain built up under reaction conditions.…”
Section: Introductionmentioning
confidence: 99%
“…While X-ray diffraction provides average information 3 , atomic resolution is achieved using aberration-corrected transmission electron microscopy (AC-TEM) such as the work of Walsh et al 10 showing local strain variations due to the nanoparticle-support interface. Under reaction conditions, the nanoparticle structure can present dynamic restructuration, faceting process [11][12][13][14] , requiring in situ and operando imaging tools 15 . Although the development of environmental TEM enables to image catalysts under reactive conditions, as demonstrated by Vendelbo et al 11 by in situ TEM following the oscillatory behaviour of Pt nanoparticles during CO oxidation reaction, three-dimensional strain information is lacking.…”
Understanding catalysts strain dynamic behaviours is crucial for the development of cost-effective, efficient, stable and long-lasting catalysts. Here, we reveal in situ three-dimensional strain evolution of single gold nanocrystals during a catalytic CO oxidation reaction under operando conditions with coherent X-ray diffractive imaging. We report direct observation of anisotropic strain dynamics at the nanoscale, where identically crystallographically-oriented facets are qualitatively differently affected by strain leading to preferential active sites formation. Interestingly, the single nanoparticle elastic energy landscape, which we map with attojoule precision, depends on heating versus cooling cycles. The hysteresis observed at the single particle level is following the normal/inverse hysteresis loops of the catalytic performances. This approach opens a powerful avenue for studying, at the single particle level, catalytic nanomaterials and deactivation processes under operando conditions that will enable profound insights into nanoscale catalytic mechanisms.
“…The possibility of using reactive environments during the measurement makes BCDI an ideal technique to probe dynamic changes and observe the evolution of defects' distribution. In recent years, in situ BCDI has revealed the dynamics occurring during catalytic processes [15][16][17] , strain mapping and nucleation dislocation during ionic diffusion in Lithium-ion batteries [18][19][20][21][22] , as well as the defect evolution during the hydriding phase transformation of palladium nanocrystals [23][24][25] . In ref.…”
Section: Bragg Coherent Diffraction Imaging (Bcdi) Is a Lensless Techmentioning
Palladium absorbs large volumetric quantities of hydrogen at room temperature and ambient pressure, making the Pd-H system a promising candidate for hydrogen storage. Here, we use Bragg coherent diffraction imaging to map the strain associated with defects in three dimensions before and during the hydride phase transformation of an individual octahedral palladium nanoparticle, synthesized by using the seed-mediated approach. The displacement distribution imaging unveils the location of the seed nanoparticle in the final nanocrystal. By comparing our experimental results with a finite-element model, we verify that the seed nanoparticle causes a characteristic displacement distribution of the larger nanocrystal. During the hydrogen exposure, the hydride phase is predominantly formed on one tip of the octahedra, where there is a high number of lower coordinated Pd atoms. Our experimental and theoretical results provide an unambiguous method for future structure optimization of seed-mediated nanoparticles growth and in the design of palladium-based hydrogen storage systems.
“…Until now, in situ plane-wave CDI/ptychographic CDI has been reported only in the Bragg geometry for plane-wave CDI and only in the transmission geometry for ptychographic CDI. With the use of in situ plane-wave CDI in the Bragg geometry (Robinson & Harder, 2009), topological defect dynamics (Ulvestad et al, 2015) and catalysis-induced strain (Suzana et al, 2019) in crystalline nanoparticles have been studied. In in situ ptychographic CDI in the transmission geometry, lithium zirconate has been observed in air and CO 2 at atmospheric pressure at temperatures exceeding 873 K (Høydalsvik et al, 2014).…”
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
