Join the Department of Materials Science and Engineering for light refreshments and a discussion lead by Dr. Stephen House of the University of Pittsburgh. He is a faculty candidate for a TEM position.
The structural details of a material significantly impact its properties and behavior. With nano-scale materials, such as nanoparticle catalysts, even small (nano- to atomic-scale!) structural and morphological differences can result in dramatically disparate performance.Structure pathways and transient states are not observable by post-mortem examination alone. In this seminar, I will discuss how transmission electron microscopy (TEM) can be applied to directly study the nano-scale structure and dynamics of such systems using examples primarily from two categories of materials. The first involves the application of electron tomography (3D) and in situ TEM to ball-milled and nano-confined light metal hydrides for on-board automotive hydrogen storage to reveal why certain systems experienced difficulty (or not) reaching their predicted potentials. The second covers the characterization of mono- and bi-metallic nanoparticle catalysts through (a) the development of quantitative STEM techniques for measuring particle mass and 3D structure, and (b) a correlative multi-scale characterization approach that tightly integrates TEM, X-ray spectroscopy, and theoretical modeling to address structural questions in these complex, heterogeneous systems.