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Atomistic simulations reveal that the chemical reactivity of ceria nanorods is increased when tensioned and reduced when compressed promising strain-tunable reactivity; the reactivity is determined by calculating the energy required to oxidize CO to CO2 by extracting oxygen from the surface of the nanorod. Visual reactivity “fingerprints”, where surface oxygens are colored according to calculated chemical reactivity, are presented for ceria nanomaterials including: nanoparticles, nanorods, and mesoporous architectures. The images reveal directly how the nanoarchitecture (size, shape, channel curvature, morphology) and microstructure (dislocations, grain-boundaries) influences chemical reactivity. We show the generality of the approach, and its relevance to a variety of important processes and applications, by using the method to help understand: TiO2 nanoparticles (photocatalysis), mesoporous ZnS (semiconductor band gap engineering), MgO (catalysis), CeO2/YSZ interfaces (strained thin films; solid oxide fuel cells/nanoionics), and Li-MnO2 (lithiation induced strain; energy storage).

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Energy-filtered transmission electron microscopy is used to image the nanocomposite FeAl+Y2O3, an oxide-dispersion-strengthened intermetallic alloy, over a tilt range of ±60° using inelastically scattered electrons only. The properties of electron spectroscopic imaging are exploited to recover a projection relationship between the three-dimensional chemical concentration distribution and the micrographs. This allows recovery of the full information on volume shape, distribution, and homogeneity of the buried nanoparticles by backprojection. Restrictions to low atomic number, common in bio-objects, are here overcome at the expense of higher electron exposures.