Adsorption of Carbon Monoxide on Pd/SiO2/Si(111) Studied by Core-Level Photoemission

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Title:Adsorption of Carbon Monoxide on Pd/SiO2/Si(111) Studied by Core-Level Photoemission
Creators:
Bastl, Zdeněk
Šarapatka, Tomáš
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 63, 11, pp. 1793-1802
Uncontrolled Keywords:Pd-Clusters, Pd/SiO2/Si(111), X-ray photoelectron spectroscopy, CO Adsorption, Palladium

Abstract

X-Ray photoelectron spectroscopy (XPS) has been used to study the adsorption of carbon monoxide on Pd dispersed on oxidized Si(111) surface. A fraction of the deposited Pd diffusing at room temperature to the SiO<sub>2</sub>/Si interface increases with decreasing SiO<sub>2</sub> thickness. For oxide layers thinner than ≈1 nm, almost all deposited Pd diffuses to SiO<sub>2</sub>/Si interface forming there Si silicide. Consequently, the amount of adsorbed CO is dependent on the thickness of the thermally grown SiO<sub>2</sub> layer. Two different chemical states of adsorbed carbon atoms, the population of which depends on the amount of the Pd deposited, are observed in the C (1s) spectra of adsorbed CO. Adsorption activity of Pd clusters does not depend on whether n- or p-type Si is used. Comparison of the experimental Pd/CO concentration ratios with those calculated assuming several different modes of the Pd growth on SiO<sub>2</sub>/Si points to the pseudo-Stranski-Krastanow mode (flat clusters with incomplete condensation of the first layer) at 300 K. Changes in charge balance across the Pd/SiO<sub>2</sub>/Si interface caused by CO adsorption are discussed in terms of the surface photovoltage effect and work function variation.

Title:Adsorption of Carbon Monoxide on Pd/SiO2/Si(111) Studied by Core-Level Photoemission
Creators:
Bastl, Zdeněk
Šarapatka, Tomáš
Uncontrolled Keywords:Pd-Clusters, Pd/SiO2/Si(111), X-ray photoelectron spectroscopy, CO Adsorption, Palladium
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:63
Number:11
Page Range:pp. 1793-1802
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19981793UNSPECIFIED
ID Code:1421
Item Type:Article
Deposited On:06 Feb 2009 17:09
Last Modified:06 Feb 2009 16:09

Citation

Bastl, Zdeněk; Šarapatka, Tomáš (1998) Adsorption of Carbon Monoxide on Pd/SiO2/Si(111) Studied by Core-Level Photoemission. Collection of Czechoslovak Chemical Communications, 63 (11). pp. 1793-1802. ISSN 0010-0765

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