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COLL 1 Vibrationally Mediated Chemistry at the Gas-Surface COLL 1 Vibrationally mediated chemistry at the gas-surface interface Arthur L Utz(1), [email protected], 62 Talbot Ave, Medford MA 02155, United States ; Victoria Campbell(1); Deno DelSesto(1); Nan Chen(1); Eric Peterson(1); Eric Dombrowski(1); Yongli Huang(1). (1) Department of Chemistry, Tufts University, Medford MA 02155, United States Vibrationally energized polyatomic molecules are abundant under thermal processing conditions, and vibrational energy can play an important role in activating reactions at the gas-surface interface. Beam-surface scattering studies performed with laser-excited and internal state selected molecules provide insight into how vibrational excitation of the molecule and surface activate reaction. Observations of mode- and bond-selective reactivity reveal the extent of vibrational energy redistribution prior to reaction. Surface- temperature-dependent studies using internal-state-selected gas-phase reagents show that surface vibrations can play a dramatic role in promoting methane activation on Ni. The presentation will highlight recent results from our lab that explore the role of surface excitation and of vibrationally hot precursor molecules in promoting reaction at the gas- surface interface. COLL 2 Electronically nonadiabatic chemical dynamics at metal surfaces Alec M. Wodtke(1)(2), [email protected], Fassberg 11, Goettingen Lower Saxony 37077, Germany . (1) Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, Goettingen Lower Saxony 37077, Germany (2) Department of Physical Chemistry, Georg August University of Goettingen, Goettingen Lower Saxony 37077, Germany Developing a predictive understanding of surface chemistry based on the first principles of Physics must include possible breakdown of the Born-Oppenheimer approximation. Reaching this goal means progressing beyond what is now possible for gas-phase bimolecular reactive encounters. This represents one of the most important challenges to current research in chemical physics; since, to the extent that the Born-Oppenheimer approximation breaks down, we have no predictive theory of surface chemistry. This means we are working in an exciting environment where new phenomena might be discovered through experiments and inspire new theoretical developments. This lecture will present recent experimental results that demonstrate the importance of Born- Oppenheimer breakdown. I will emphasize quantitative measurement that can be directly compared to dynamical theories that go beyond the Born-Oppenheimer Approximation. White et al., Nature, 2005. 433: 503; Huang et al., Science, 2000. 290: 111; Cooper et al., Chem. Sci., 2010. 1: 55; Shenvi et al., Science, 2009. 326: 829; Larue et al., Phys.Chem.Chem.Phys., 2011. 13:97. COLL 3 Ethanol electrooxidation on Pt(111)-supported SnOx: A surface science approach to study the metal oxide-metal interaction in electrocatalysis Wei-Ping Zhou(1), [email protected], Bldg 555 Brookhaven Ave, Upton New York, United States ; Stephanus Axnanda(1); Michael G White(1); Radoslav R. Adzic(1). (1) Chemistry Department, Brookhaven National Laboratory, Upton New York 11973, United States Recent studies demonstrated that the SnOx promoted Pt electrocatalysts have high performance in ethanol electrooxidation and may have the potential for use in direct ethanol fuel cells. However, the nature of the active phase in SnOx/Pt nanocatalysts still remains elusive and their performance is highly dependent on the preparation methods and activation conditions. To examine the activity – SnOx-Pt interaction correlation, we used a surface science approach to prepare and characterize the model catalyst system consisting of SnOx nanoislands grown on a Pt(111) electrode. The SnOx/Pt(111) model systems were characterized using XPS and LEIS and then the ethanol oxidation reaction (EOR) was studied under electrochemical conditions without exposure to air. Correlating the surface properties of the SnOx/Pt(111) electrode with the observed EOR activity will provide critical information for improving the understanding of SnOx-Pt interaction in the EOR reaction. A detailed discussion of these findings will be presented at the meeting. COLL 4 Using nanoscale amorphous solid films to create and study deeply supercooled liquids Bruce D Kay(1), [email protected], PO Box 999 MSN K8-88, Richland Washington 99352, United States ; Scott Smith(1). (1) Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland Washington 99352, United States Molecular beam vapor deposition on cryogenic substrates is known to produce amorphous solid films. When heated above their glass transition these films transform into deeply supercooled liquids. These nanoscale liquid films can be used to study kinetic processes such as diffusion, isotope exchange, and crystallization in unprecedented detail. This talk will highlight our recent advances in this area with a focus on hydrogen-bonded liquids such as water and alcohols. This work was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. The research was performed using EMSL, a national scientific user facility sponsored by DOE's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory, which is operated by Battelle, operated for the U.S. DOE under Contract DE-AC05-76RL01830. COLL 5 Shock compression dynamics with molecular resolution Dana D Dlott(1), [email protected], Box 01-6 CLSL, Urbana IL, United States ; Christopher M Berg(1); Alexei Lagutchev(1). (1) School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana IL 61801, United States Detonation of energetic materials takes place within a traveling interfacial structure called the detonation front. The detonation front travels over a typical molecule in 0.1 ps. Chemical reaction initiation occurs in a nanometer layer near the front and ignition in a micrometer layer behind the front. These processes are studied in real time using a tabletop apparatus with a femtosecond laser to study initiation and a nanosecond laser to study ignition. COLL 6 Free Radical Polymerization at the Vapor/Ionic Liquid Interface Malancha Gupta(1), [email protected], 925 Bloom Walk, HED 216, Los Angeles CA 90089-1211, United States . (1) This talk will describe vapor-phase free radical polymerization of hydrophilic and hydrophobic monomers in the presence of ionic liquids (ILs). We will explain how the polymerization kinetics at the vapor/IL interface can be varied to produce several novel polymeric structures such as films and skins. We will discuss the effect of key parameters such as deposition time, temperature, and monomer solubility. Molecular weight data and thickness measurements will be presented to show the morphology and conformality of the resulting skins and films produced at the vapor/IL interface. COLL 7 Measuring Environmental Transformation of Multi-walled Carbon Nanotubes using Integrated Thermal Analysis and Related Hyphenated Techniques Endalkachew Sahle-Demessie(1), [email protected], Nationla Risk Management Research Lab, 26 W. Martin Luther King Dr,, Cincinnati OH 45268, United States ; Amy Zhao(1); Andrew W. Salamon(2); Stephen Harrmon(1). (1) Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati OH 45040, United States (2) Perkin Elmer Inc., 710 Bridgeport Ave. Shelton, CT 06484, United States With the increase in the commercialization of exploiting engineered nanomaterials increases, the future of nanotechnology rests upon approaches to making new, useful nanomaterials and testing them in complex systems. Unlike the mature analytical market for bulk and molecular matter, the current advance from discovery to application in nanotechnology is constrained due to the lack of quick, rapid, reliable and low cost technique. Thermogravimetric analysis (TGA) has demonstrated to be an effective technique to confirm dimensions and homogeneity of multiwalled carbon nanotubes (MWCNT) including the presence of trace metal catalyst or other contaminates, and structural defects. We have also demonstrated the use of TGA to study effects of exposing MWCNT to oxidative atmosphere that causes environmental aging which increases defect sites, reduces their structural stability and increase chemical functionalization. The results were compared with other characterization techniques such as spectroscopic, X-ray diffraction and transmission electron spectroscopic. TGA- GC-MS emitted gas analysis has also been used to investigate the adsorption and interaction of organic molecules with nanoparticles in the environments. COLL 8 Aggregation and adsorption of silver nanoparticles: Effects of surface modification by humic substances Olha Furman(1), [email protected], One Bear Place #97354, Waco Texas 76798, United States ; Boris Lau(1); Sascha Usenko(2). (1) Department of Geology, Baylor University, Waco Texas 76798, United States (2) Department of Environmental Science and Aquatic Systems Research, Baylor University, Waco Texas 76798, United States The behavior of engineered nanoparticles, many of which serve as contaminant scavengers, is an important topic for environmental health and safety. The impacts of humic acid (HA) and fulvic acid (FA) on the aggregation and adsorption kinetics of 50 nm citrate-stabilized silver nanoparticles (AgNPs) onto silica surfaces were investigated using dynamic light scattering and
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