Department of Materials Science & Mechanics
Duke University
ABSTRACT
Through practical examples, this presentation will describe the interplay between phases competing for stability at the nano-scale focusing on their effects on catalytic reactions. By leveraging the complex balance of power between surface-tension and surface-energy contributions, we will address: 1) reduced solubility in iron nano-catalysts for carbon nanotubes production and thermodynamic limit of the growth [1], 2) size-induced viscosity -the kinetic counterpart of dynamic coexistence- with "super-1/R" effects on reaction speeds (dynamic renormalization of the time frame) [2], 3) self-consistent variational approaches to the hierarchy of shape of nano-catalysts [3], and, if time allows, 4) size-dependent Wulff plots [4].
[1] Phys. Rev. Lett. 100, 195502 (2008). [2] ACS -NANO 4(11), 6950-6956 (2010). [3] ACS-NANO 5(1), 247-254 (2011). [4] Chepulskii and Curtarolo, Ab Initio Insights on the Shapes of Platinum Nanocatalysts II: The extension of the Wulff construction, submitted to ACS-NANO (2011).
Bio: After studying Electrical Engineering and Physics in Padova, Italy, SC received his PhD in Materials Science from MIT in 2003. Since then, he was faculty of Materials Science and Physics at Duke University. During his time at Duke, SC received the ONR-Young-Investigator, the NSF-Career, and the Presidential PECASE Awards in addition to the International Union of Pure and Applied Physics - Young Scientist Prize in Computational Physics. SC was promoted to Associate in Oct. 2008 and to Full Professor in Feb. 2012. Currently he has more than 75 refereed publications and more than 100 invited departmental seminars and talks in national and international conferences. At Duke University, the SC's group released the ``on-line ab-initio binary phase diagram database'' containing free energy information for more than 1,000 binary intermetallic alloys (materials.duke.edu/apool.html) and the ``high-throughput electronic structure consortium repository'' containing more than 15,000 fully ab-initio electronic characterization for inorganic compounds (aflowlib.org).