Understanding CeO₂‐Based Nanostructures through Advanced Electron Microscopy in 2D and 3D

Abstract

Engineering morphology and size of CeO2‐based nanostructures on a (sub)nanometer scale will greatly influence their performance; this is because of their high oxygen storage capacity and unique redox properties, which allow faster switching of the oxidation state between Ce4+ and Ce3+. Although tremendous research has been carried out on the shape‐controlled synthesis of CeO2, the characterization of these nanostructures at the atomic scale remains a major challenge and the origin of debate. The rapid developments of aberration‐corrected transmission electron microscopy (AC‐TEM) have pushed the resolution below 1 Å, both in TEM and in scanning transmission electron microscopy (STEM) mode. At present, not only morphology and structure, but also composition and electronic structure can be analyzed at an atomic scale, even in 3D. This review summarizes recent significant achievements using TEM/STEM and associated spectroscopic techniques to study CeO2‐based nanostructures and related catalytic phenomena. Recent results have shed light on the understanding of the different mechanisms. The potential and limitations, including future needs of various techniques, are discussed with recommendations to facilitate further developments of new and highly efficient CeO2‐based nanostructures.

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

“…An increase in the particle size expectedly decreases the low‐temperature activity of the catalysts. In accordance with a recent review by Zhang et al ., the morphologies and sizes of CeO 2 ‐based nanostructures on the (sub)nanometre scale will greatly influence their performance.…”

Recent Progress on Revealing 3D Structure of Electrocatalysts Using Advanced 3D Electron Tomography: A Mini Review

“…Thus, exposed facets of CeO 2 could be understood in 3D ( Kaneko et al, 2007 ; Tan et al, 2011 ). More interestingly, by using EELS -tomography, the distribution of Ce 3+ /Ce 4+ could be reconstructed and imposed on resolved facets in 3D ( Goris et al, 2014 ; Zhang et al, 2019b ). Such manner of microstructure investigation can greatly improve the understanding of catalysts’ behavior.…”

A multiscale in situ high temperature high resolution transmission electron microscopy study of ThO2 sintering

“…These works have experimentally evidenced nanometric / atomic scale processes that can drive the first stage of sintering. Most of the materials that have been studied are metallic 12,13 or CeO2 nanoparticles [14][15][16][17] .…”