title: In situ x-ray photoelectron spectroscopy of model catalysts: at the edge of the gap.
abstract: We present high-pressure x-ray photoelectron spectroscopy (HP-XPS) and first-principles kinetic Monte Carlo study addressing the nature of the active surface in CO oxidation over Pd(100). Simultaneously measuring the chemical composition at the surface and in the near-surface gas phase, we reveal both O-covered pristine Pd(100) and a surface oxide as stable, highly active phases in the near-ambient regime accessible to HP-XPS. Surprisingly, no adsorbed CO can be detected during high CO(2) production rates, which can be explained by a combination of a remarkably short residence time of the CO molecule on the surface and mass-transfer limitations in the present setup.
authors.affiliation: Division of Synchrotron Radiation Research, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Blomberg
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Hoffmann
authors.affiliation: Division of Synchrotron Radiation Research, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Gustafson
authors.affiliation: Division of Synchrotron Radiation Research, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: N M
authors.initials: NM
authors.lastname: Martin
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
authors.forename: V R
authors.initials: VR
authors.lastname: Fernandes
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
authors.forename: A
authors.initials: A
authors.lastname: Borg
authors.affiliation: ALS, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Liu
authors.affiliation: ALS, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: R
authors.initials: R
authors.lastname: Chang
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Matera
authors.affiliation: Department Chemie, Technische Universität München, Lichtenbergstrasse 4, D-85747 Garching, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Reuter
authors.affiliation: Division of Synchrotron Radiation Research, Lund University, Box 118, SE-221 00 Lund, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Lundgren