Journal ArticleDOI
A molecular beam investigation of the catalytic oxidation of CO on Pd (111)
T. Engel,Gerhard Ertl +1 more
TLDR
In this paper, a detailed investigation of the steady-state and nonsteady-state reaction CO+1/2O2→CO2 on Pd (111) has been carried out with the molecular beam technique.Abstract:
A detailed investigation of the steady‐state and nonsteady‐state reaction CO+1/2O2→CO2 on Pd (111) has been carried out with the molecular beam technique. It could be shown conclusively that the reaction proceeds between two adsorbed species (Langmuir–Hinshelwood mechanism) throughout the temperature and pressure range investigated. For low CO coverages, the activation energy of the reaction was determined to be 25 kcal/mole, whereas at moderate CO coverages, a rearrangement of the oxygen adlayer takes place resulting in a reduction of the activation energy to 14 kcal/mole. It is not possible to formulate a simple kinetic expression for the reaction rate which is valid over the entire range of temperatures and pressures due to changes in the adsorption rate for O2, coadsorption of CO and O2, to diffusion in the adlayer, and to changes in the geometrical arrangement within the adlayer with varying coverage.read more
Citations
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Journal ArticleDOI
Mechanism of CO oxidation reaction on O-covered Pd(111) surfaces studied with fast x-ray photoelectron spectroscopy: change of reaction path accompanying phase transition of O domains.
TL;DR: The mechanism of CO oxidation on O-precovered Pd(111) surfaces by means of fast x-ray photoelectron spectroscopy (XPS) is studied, finding that CO molecules in a high-density phase formed under CO exposure react with oxygen atoms, leading to quite a small apparent activation energy.
Journal ArticleDOI
Fundamental Insight into the Substrate‐Dependent Ripening of Monodisperse Clusters
TL;DR: In this article, the authors explored the fundamental factors that control cluster-ripening mechanisms, and deposited truly monodisperse Pd clusters onto three different model catalysts: bare Rh(111), gra
Book ChapterDOI
Catalytic Activation of Dioxygen
TL;DR: In this paper, the interaction of dioxygen with dihydrogen or carbon monoxide often serve as model reactions for fundamental research in heterogeneous catalysis, and some attempts have been made recently to utilize the catalytic oxidation of fuels for energy production.
Journal ArticleDOI
Cluster chemistry: size-dependent reactivity induced by reverse spill-over.
Martin A. Röttgen,Stéphane Abbet,Ken Judai,Jean-Marie Antonietti,Anke S. Wörz,Matthias Arenz,Claude R. Henry,Ulrich Heiz +7 more
TL;DR: The results indicate that, for small clusters, the reaction probability of an impinging CO molecule is independent of whether it is supplied by diffusion or direct flux, and for larger clusters, a reduced reaction probability is found forCO supplied by reverse spill-over compared to CO supplied by direct flux.
Journal ArticleDOI
Transition from molecule to solid state: reactivity of supported metal clusters.
Georges Sitja,Séverine Le Moal,Séverine Le Moal,Maxence Marsault,Guido Hamm,Frédéric Leroy,Claude Henry +6 more
TL;DR: Unprecedented accuracy on the determination of the particle size has been achieved here by using a regular array of metal clusters exhibiting a size dispersion down to the ultimate limit of a Poisson distribution, which allows getting rid of the convolution effects that generally occur when considering particles grown through other techniques.
References
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Journal ArticleDOI
Molecular beam study of the apparent activation barrier associated with adsorption and desorption of hydrogen on copper
TL;DR: In this article, the adsorption and desorption of H2 on the (100, (110), and stepped (310) crystal faces of copper was studied. And the energy and incident angle of the H2 beam were measured by a rotatable mass spectrometer.
Journal ArticleDOI
Adsorption of oxygen and oxidation of CO on the ruthenium (001) surface
TL;DR: The adsorption of oxygen on the ruthenium (001) surface has been studied using a combination of techniques: LEED/Auger, Kelvin probe contact potential changes, and flash desorption mass spectrometry as mentioned in this paper.
Journal ArticleDOI
Interaction of NO and O2 with Pd(111) surfaces. II
TL;DR: The surface region of Pd(111) is characterized by three different types of oxygen atoms, which may be distinguished by their thermal, chemical, structural and electronic properties as discussed by the authors.
Journal ArticleDOI
Angular distribution of hydrogen molecules desorbed from metal surfaces
TL;DR: In this paper, the angular distribution of desorbeded H2 molecules has been studied and the measured angular distributions are strongly peaked forward, indicating that they are not uniformly distributed.
Journal ArticleDOI
Chemisorption und katalytische Reaktion von Sauerstoff und Kohlenmonoxid an einer Palladium (110)-Oberfläche
Gerhard Ertl,P. Rau +1 more
TL;DR: In this article, the adsorption and catalytic reaction of oxygen and carbon monoxide on a Pd(110) surface has been studied by means of low energy electron diffraction (LEED) and mass spectrometric techniques.
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