Strain and Architecture-Tuned Reactivity in Ceria Nanostructures; Enhanced Catalytic Oxidation of CO to CO2

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• 作者：Thi X. T. Sayle ; Michelle Cantoni ; Umananda M. Bhatta ; Stephen C. Parker ; Simon R. Hall ; G眉nter M枚bus ; Marco Molinari ; David Reid ; Sudipta Seal ; Dean C. Sayle
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：May 22, 2012
• 年：2012
• 卷：24
• 期：10
• 页码：1811-1821
• 全文大小：893K
• 年卷期：v.24,no.10(May 22, 2012)
• ISSN：1520-5002

文摘

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 鈥渇ingerprints鈥? 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).

Keywords:

ceria nanoparticle; mesoporous; nanorod; molecular dynamics; simulated crystallization; aberration corrected TEM; catalysis