Visualization of the distribution of anatase and rutile TiO2 crystals in Au/TiO2 powder catalysts by STEM–EELS spectrum imaging. (23rd May 2014)

• Record Type: Journal Article
• Authors: Akita, Tomoki; Kohyama, Masanori; Yurimoto, Hisayoshi
• Is Part Of: Surface and interface analysis. Volume 46:Number 12/13(2014)
• Page Start: 1249
• Page End: 1252
• Publication Date: 2014-05-23
• Subjects: Surfaces (Physics) -- Periodicals; Surface chemistry -- Periodicals; Thin films -- Periodicals; 541.33
• DOI: 10.1002/sia.5582
• Languages: English
• ISSNs: 0142-2421

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Gold nanoparticles deposited on TiO₂ supports exhibit high catalytic activity for various chemical reactions such as low‐temperature CO oxidation. The catalytic performance is sensitive to the structure of the TiO₂ supports, as reported in the epoxidation of propylene. TiO₂ powder (P‐25), widely used as the support for metal catalysts, contains both anatase and rutile TiO₂ phases. It is important to distinguish these two crystalline phases at the nanoscale in order to understand the effect of the support structure in Au/TiO₂ catalysis. In this study, the two‐phase distribution is analyzed using scanning transmission microscopy–electron energy‐loss spectroscopy (STEM–EELS). The distribution is revealed through multilinear least‐squares fitting on the basis of the difference in the energy‐loss near‐edge structure. The results obtained indicate that Au particles are preferentially deposited on rutile TiO₂ in the deposition/precipitation process. The STEM–EELS spectrum imaging method, with its high energy and spatial resolutions, can be employed to determine the distribution of crystal phases, components, and valence states. Copyright © 2014 John Wiley &amp; Sons, Ltd.</p> </abstract>