There are two major aims of our studies: 1) to determine the surface structure and chemical bonding of metals, ionic solids, adsorbed organic monolayers, and polymers; 2) to apply the knowledge to understanding, on the molecular level, important macroscopic surface phenomena. These are heterogeneous catalysis and the friction, hardness, and biocompatibility of polymers. The experimental techniques most frequently used in these studies include low energy electron diffraction (LEED),various electron spectroscopies, the scanning tunneling microscope (STM),the atomic force microscope (AFM), vibrational spectroscopy by laser sum frequency generation (SFG) and UV-raman, mass spectroscopy, and gas chromatography. We utilize single crystal surfaces prepared in ultra high vacuum and nano-cluster arrays prepared by electron beam lithography.
The hydrogenation and dehydrogenation of cyclohexene, ethylene hydrogenation, and CO oxidation are studied on platinum and rhodium single crystal surfaces at atmospheric pressures using SFG and STM and at solid-liquid interfaces using SFG. The catalytic polymerization of ethylene and propylene are investigated on the MgCl2/TiCl4/Al(C2H5)3 model catalyst by a combination of electron spectroscopies, UV-raman spectroscopy, and SFG. The catalytic conversion of hydrocarbons (n-hexane, etc.) is studied using palladium crystal surfaces. Platinum and silver nano-cluster arrays are fabricated by electron beam lithography and used for hydrocarbon conversion and for partial oxidation of ethylene to ethylene oxide, respectively.