Aberration-corrected scanning transmission electron microscopy provides unique new insights into catalytic materials.  The ability to image at the sub-�ngstrom resolution can be used to obtain fundamental understanding of the size and shape of heavy metal clusters and their relationship to carbon species on a catalyst support.  In this presentation we will discuss the effect of reduction temperatures on the Pt cluster size on ?-Al2O3 and relate the atom-resolved cluster size to the cluster shape.  The advanced analytical capabilities allow us to determine the specific location of carbonaceous deposits, which can then be used to determine the mechanism for catalyst deactivation.  For example, the chemical maps of a used Pt-Re/?-Al2O3 catalyst show the relation between the metal clusters and associated carbonaceous deposits.  Another example of the unique capability is the ability to obtain a chemical tomogram that illustrates the spatial relationship between Pd crystallites on a catalyst support.  Issues associated with characterizing catalysts by electron microscopy and the future directions will be discussed.

Application of aberration-corrected scanning transmission electron microscopy to the characterization of catalysts and imaging sub-nanometer clusters

247th National Meeting (2014)

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