Direct Visualization and Control of Atomic Mobility at 100 Surfaces of Ceria in the Environmental Transmission Electron Microscope

Matthieu Bugnet (1) , S.H. Overbury , Z.L. Wu , T. Epicier (1)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]

Ceria is one of the world's most prominent material for applications in heterogeneous catalysis, as catalyst support or catalyst itself. Despite an exhaustive literature on the structure of reactive facets of CeO2 in line with its catalytic mechanisms, the temporal evolution of the atomic surface structure exposed to realistic redox conditions remains elusive. Here, we provide a direct visualization of the atomic mobility of cerium atoms on 100 surfaces of CeO2 nanocubes at room temperature in high vacuum, O2, and CO2 atmospheres in an environmental transmission electron microscope. Through quantification of the cationic mobility, we demonstrate the control of the surface dynamics under exposure to O2 and CO2 atmospheres, providing opportunities for a better understanding of the intimate catalytic mechanisms. © 2017 American Chemical Society.

Mots clés: Atoms; Carbon dioxide; Catalysis; Catalysts; Cerium compounds; Electron microscopy; Electrons; Surfaces; Visualization; Atomic mobility; Catalytic mechanisms; Direct visualization; Environmental transmission electron microscopes; Environmental transmission electron microscopy; facet; Nanocubes; Temporal evolution; High resolution transmission electron microscopy

Domaines: Matériaux

Matthieu Bugnet, S.H. Overbury, Z.L. Wu, T. Epicier. Direct Visualization and Control of Atomic Mobility at 100 Surfaces of Ceria in the Environmental Transmission Electron Microscope. Nano Letters, 2017, 17 (12), pp.7652-7658. ⟨10.1021/acs.nanolett.7b03680⟩. ⟨hal-01804255⟩