Passos, Aline R.
Manente, Luiza M.
Suzana, Ana F.
Total Authors: 7
 Brazilian Ctr Res Energy & Mat CNPEM, Brazilian Synchrotron Light Lab LNLS, BR-13083970 Campinas, SP - Brazil
 UNESP, Inst Quim, Rua Prof Francisco Degni, BR-14800900 Araraquara, SP - Brazil
 Argonne Natl Lab, Adv Photon Source, 9700 South Cass Ave, Argonne, IL 60439 - USA
Total Affiliations: 3
SEP 18 2020.
Web of Science Citations:
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. Direct visualisation of site-specific strain variations of catalysts is needed to better understand catalytic properties. Here, the authors determine with attojoule precision that the well-known catalytic hysteresis phenomenon occurs at single particle level and involves three-dimensional strain field. (AU)