Research Interests:

Stephen J. Pennycook is a Corporate Fellow in the Materials Science and Technology Division at Oak Ridge National Laboratory, leader of the Electron Microscopy Group and an adjoint professor of physics at Vanderbilt University. Current research interests focus on the development of atomic-resolution Z?]contrast scanning transmission electron microscopy and electron energy loss spectroscopy with applications in the field of catalysis, materials physics and nanoscience. Pennycook has given over 150 invited presentations at international conferences and has over 300 journal publications, more than 50 in Science, Nature or Physical Review Letters, 18 book chapters and 3 encyclopedia articles. He is a Fellow of the American Physical Society, the American Association for the Advancement of Science and the Institute of Physics, and has been awarded an R&D 100 Award, the Microbeam Analysis Society Heinrich Award, the Materials Research Society Medal and the Thomas Young Medal of the Institute of Physics.

Selected current research themes include:

• Imaging of Pt trimers on g-alumina explains the origin of anomalous Pt–Pt distances in the Pt/Alumina System.
• Imaging of catalyst clusters and individual atoms in 3D.
• Why dopants adsorbed as single atoms prevent degradation of catalysts.
• Dual nanoparticle/substrate control of catalytic dehydrogenation by single atom imaging and theory.
• The origin of low-temperature catalytic CO oxidation by supported Au nanoparticles by direct imaging and first-principles theory.
• The role of the nanoscale in the catalytic fixation of CO2 on CdSe.
• Catalytic nucleation of single-walled carbon nanotubes on a metal surface.