AVS 61st International Symposium & Exhibition
    Surface Science Wednesday Sessions
       Session SS-WeA

Paper SS-WeA4
The Structure Sensitivity of L and D Tartaric Acid Explosive Decomposition on Copper Surface Structure Spread Single Crystals

Wednesday, November 12, 2014, 3:20 pm, Room 309

Session: Chirality and Enantioselectivity on Surfaces
Presenter: Aaron Reinicker, Carnegie Mellon University
Authors: A. Reinicker, Carnegie Mellon University
B.S. Mhatre, Carnegie Mellon University
B.S. Holsclaw, Carnegie Mellon University
E.C.H. Sykes, Tufts University
A.J. Gellman, Carnegie Mellon University
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There are many catalytic reactions that are sensitive to the surface structure of the catalyst. Surface Structure Spread Single Crystals (S4Cs) expose a continuous distribution of crystal planes across their surfaces. Each point on the S4Cs has a different local crystallographic orientation that can be determined from the shape of the S4Cs and the orientation of its bulk crystal lattice vectors. Crystal planes on these S4Cs contains terraces, monatomic steps, and kinks and can be described as chiral with an R or an S orientation. When coupled with spatially resolved surface analysis techniques, S4Cs can be used to study the effects of surface structure and chirality on surface chemistry across a broad, continuous distribution of crystal planes. In this work, the structure sensitivity of L and D tartaric acid explosive decomposition was studied using a Cu(111)±10° S4C. Isothermal Temperature Programmed Desorption (TPD) was used in which each sample was held at a temperature >20 K below the temperature of peak decomposition observed in a standard (TPD) experiment until the decomposition reaction occurred. Spatially resolved X-ray Photoelectron Spectroscopy (XPS) was performed to determine which crystal planes on the Cu(111)±10° S4C had undergone explosive decomposition after quenching the temperature of the sample at the decomposition peak during an isothermal TPD. Quenching the sample at different times during the isothermal TPD decomposition peak was implemented to visualize the stages of reaction on the Cu(111)±10° S4C surface. It was found that both D-tartaric acid and L-tartaric acid reacted on crystal planes with (100) steps before crystal planes with (111) steps and the surface structure had more of an effect on the explosive decomposition of tartaric acid than the surface chirality.