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SYCR: Symposium Chemical Reactions on Nanomaterials: Progress from in-situ Experimental Studies and Theoretical Investigations

SYCR 1: Chemical Reactions on Nanomaterials

SYCR 1.1: Hauptvortrag

Donnerstag, 26. März 2009, 14:00–14:30, BAR SCHÖ

Reactivity trends in CO oxidation from ultrahigh vacuum to elevated pressures — •Wayne Goodman — Texas A&M University, College Station, TX, USA

CO oxidation on Ru, Pd, Rh, and Pt surfaces has been investigated between 10-8 - 10 Torr and for a variety of temperatures and O2/CO ratios. Polarization modulation reflectance absorption infrared spectroscopy (PM-RAIRS) was used to identify the CO coverage as a function of the reaction rate for a variety of conditions up to 10 Torr. For reaction pressures less than 10-6 Torr, X-ray photoelectron spectroscopy (XPS) was used to measure the surface coverages of CO and Oads. A clear continuum with respect to reaction rates, surface composition, and overall mechanism is apparent over the entire pressure range investigated, i.e. there is no evidence of a pressure gap.