title: CO oxidation on Pt(111) at near ambient pressures.
abstract: The oxidation of CO on Pt(111) was investigated simultaneously by near ambient pressure X-ray photoelectron spectroscopy and online gas analysis. Different CO:O2 reaction mixtures at total pressures of up to 1 mbar were used in continuous flow mode to obtain an understanding of the surface chemistry. By temperature-programmed and by isothermal measurements, the onset temperature of the reaction was determined for the different reactant mixtures. Highest turnover frequencies were found for the stoichiometric mixture. At elevated temperatures, the reaction becomes diffusion-limited in both temperature-programmed and isothermal measurements. In the highly active regime, no adsorbates were detected on the surface; it is therefore concluded that the catalyst surface is in a metallic state, within the detection limits of the experiment, under the applied conditions. Minor bulk impurities such as silicon were observed to influence the reaction up to total inhibition by formation of non-platinum oxides.
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Krick Calderón
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Grabau
authors.affiliation: MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, Rerrich Béla tér 1, 6720 Szeged, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Óvári
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Kress
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
authors.forename: H-P
authors.initials: HP
authors.lastname: Steinrück
authors.affiliation: Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Papp