Compatibility of field emitter studies of oscillating surface reactions with single crystal measurements

Catalytic CO oxidation on Pt

verfasst von: Yu Suchorski, R. Imbihl, V. K. Medvedev
Abstract: Kinetic oscillations in catalytic CO oxidation on Pt have been studied on large (millimeter size) single crystal planes of Pt as well as on a Pt field emitter tip that exposes different crystal facets of nanometer size. In order to examine the compatibility of results from the two types of experiments, the regions of different dynamical behavior (bifurcation diagram) have been mapped out in _pco, T-parameter space using a field electron microscope (FEM) and a field ion microscope (FIM). The comparison with the results of single crystal measurements shows that in the case of applied electrostatic fields less than 5 V nm^-1 (FEM), the field-induced effects are negligible, but they are significant for fields exceeding 12 V nm^-1 (FIM). The field-induced shift of the bifurcation diagram toward lower _pco values, observed with FIM, is explained in terms of a field-modified interaction of CO and O₂ with Pt studied here with field ion appearance energy spectroscopy. With coadsorbed lithium (submonolayer coverage), the existence range for rate oscillations is shifted toward higher _pco values. This shift is attributed to a redistribution of the electron density at the surface induced by alkali metal co-adsorption.
Organisationseinheit(en): Institut für Physikalische Chemie und Elektrochemie
Externe Organisation(en): Université libre de Bruxelles (ULB)
Typ: Artikel
Journal: Surface science
Band: 401
Seiten: 392-399
Anzahl der Seiten: 8
ISSN: 0039-6028
Publikationsdatum: 10.04.1998
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Physik der kondensierten Materie, Oberflächen und Grenzflächen, Oberflächen, Beschichtungen und Folien, Werkstoffchemie
Elektronische Version(en): https://doi.org/10.1016/S0039-6028(98)00043-0 (Zugang: Geschlossen)

BibTeX

@article{8e656713133b45a6ba62f63822f62375,
title = "Compatibility of field emitter studies of oscillating surface reactions with single crystal measurements: Catalytic CO oxidation on Pt",
abstract = "Kinetic oscillations in catalytic CO oxidation on Pt have been studied on large (millimeter size) single crystal planes of Pt as well as on a Pt field emitter tip that exposes different crystal facets of nanometer size. In order to examine the compatibility of results from the two types of experiments, the regions of different dynamical behavior (bifurcation diagram) have been mapped out in pco, T-parameter space using a field electron microscope (FEM) and a field ion microscope (FIM). The comparison with the results of single crystal measurements shows that in the case of applied electrostatic fields less than 5 V nm-1 (FEM), the field-induced effects are negligible, but they are significant for fields exceeding 12 V nm-1 (FIM). The field-induced shift of the bifurcation diagram toward lower pco values, observed with FIM, is explained in terms of a field-modified interaction of CO and O2 with Pt studied here with field ion appearance energy spectroscopy. With coadsorbed lithium (submonolayer coverage), the existence range for rate oscillations is shifted toward higher pco values. This shift is attributed to a redistribution of the electron density at the surface induced by alkali metal co-adsorption.",
keywords = "Alkali metals, Carbon monoxide, Catalysis, Field emission, Field emission microscopy, Field ion microscopy, Oxygen, Platinum, Surface chemical reaction",
author = "Yu Suchorski and R. Imbihl and Medvedev, {V. K.}",
note = "Funding Information: Financial support from the Deutsche Forschungsgemeinschaft is gratefully acknowledged. One of the authors (V.K.M.) was supported by INTAS-Ukraine Program (project 95-0186).",
year = "1998",
month = apr,
day = "10",
doi = "10.1016/S0039-6028(98)00043-0",
language = "English",
volume = "401",
pages = "392--399",
journal = "Surface science",
issn = "0039-6028",
publisher = "Elsevier",
number = "3",
}