Abstract
Recent advances in aberration corrected electron microscopy (ACEM) are providing new tools
and opportunities for studying chemical processes at gas-solid interfaces at atomic resolutions.
In the area of heterogeneous catalysis, STEM-based high-angle annular dark-field imaging (HAADF)
has provided the potential for direct observation of single heavy atoms and atom clusters.
[1]. This approach has been used to study catalytic properties by directly probing structure
development as a result of metal particle-substrate interactions, and used to explore the combined
effects of temperature, promoters, and organic ligands on the evolution of catalyst structure [2-
3]. Associated with this new tool is the potential for artifacts, such as electron beam-induced
polymerization of organic components [4], and the influence of the electron beam on heavy atom
diffusion and nanostructuring [5]. Experiments were conducted in order to develop sample
preparation techniques and imaging protocols that are suitable for achieving sub-Ångström
resolutions at ambient temperatures. In-situ heating studies were also conduct using AduroTM
heater devices manufactured using MEMS technology by Protochips Inc. (Raleigh, NC) [6].
