Strain and architecture-tuned reactivity in ceria nanostructures; Enhanced catalytic oxidation of CO to CO 2

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 CO 2 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: TiO 2 nanoparticles (photocatalysis), mesoporous ZnS (semiconductor band gap engineering), MgO (catalysis), CeO 2/YSZ interfaces (strained thin films; solid oxide fuel cells/nanoionics), and Li-MnO 2 (lithiation induced strain; energy storage). © 2012 American Chemical Society.