Photoelectron Spectroscopic Study of the Adsorption and Co-adsorption of Hydrogen and Carbon Monoxide on Iron Films

1983 ◽  
Vol 87 (6) ◽  
pp. 469-474 ◽  
Author(s):  
G. Wedler ◽  
J. Ertel
Keyword(s):  
Carbon Monoxide ◽  
Spectroscopic Study ◽  
Co Adsorption ◽  
Iron Films ◽  
Adsorption Of Hydrogen

The CO-adsorption of hydrogen and carbon monoxide on the (110) surface of iridium

1980 ◽  
Vol 97 (2-3) ◽  
pp. A249-A250
Author(s):  
D.E. Ibbotson ◽  
T.S. Wittrig ◽  
W.H. Weinberg
Keyword(s):  
Carbon Monoxide ◽  
Co Adsorption ◽  
Adsorption Of Hydrogen

The co-adsorption of hydrogen and carbon monoxide on the (110) surface of iridium†

1980 ◽  
Vol 97 (2-3) ◽  
pp. 297-308 ◽  
Author(s):  
D.E. Ibbotson ◽  
T.S. Wittrig ◽  
W.H. Weinberg
Keyword(s):  
Carbon Monoxide ◽  
Co Adsorption ◽  
Adsorption Of Hydrogen

A topological quantum-chemical study of the chemisorption of carbon monoxide on the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir

1990 ◽  
Vol 55 (8) ◽  
pp. 1907-1919
Author(s):  
Jiří Pancíř ◽  
Ivana Haslingerová
Keyword(s):  
Carbon Monoxide ◽  
Quantum Chemical ◽  
Co Adsorption ◽  
Quantum Chemical Study ◽  
Chemical Study ◽  
Dissociative Chemisorption ◽  
Frontier Orbitals ◽  
Surface Sites ◽  
Charged Surfaces ◽  
Topological Quantum

A semiempirical quantum-chemical topological method is applied to the study of the fcc (112) surfaces of Ni, Pt, Pd, Rh, and Ir and the nondissociative as well as dissociative chemisorption of carbon monoxide on them. On Ni, dissociative chemisorption is preferred to linear capture, whereas on Pd and Pt, linear capture is preferred although dissociative chemisorption is also feasible. On Rh and, in particular, on Ir, dissociative chemisorption is energetically prohibited. The high dissociative ability of the Ni surface can be ascribed to a rather unusual charge alteration and to the degeneracy of the frontier orbitals. Negative charges at the surface level are only found on the Ni and Pt surfaces whereas concentration of positive charges is established on the Rh and Ir surfaces; the Pd surface is nearly uncharged. Metals with negatively charged surfaces seem to be able to dissociate molecules of carbon monoxide. It is demonstrated that CO adsorption can take place on all metal surface sites, most effectively in the valley of the step. In all the cases studied, the attachment to the surface is found to be energetically more favourable for the carbon than for the oxygen.

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

1998 ◽  
Vol 63 (11) ◽  
pp. 1793-1802 ◽  
Author(s):  
Zdeněk Bastl ◽  
Tomáš Šarapatka
Keyword(s):  
Carbon Monoxide ◽  
Photoelectron Spectroscopy ◽  
Co Adsorption ◽  
Charge Balance ◽  
Adsorption Activity ◽  
Chemical States ◽  
Adsorbed Co ◽  
Pd Clusters ◽  
Almost All ◽  
P Type

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 SiO2/Si interface increases with decreasing SiO2 thickness. For oxide layers thinner than ≈1 nm, almost all deposited Pd diffuses to SiO2/Si interface forming there Si silicide. Consequently, the amount of adsorbed CO is dependent on the thickness of the thermally grown SiO2 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 SiO2/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/SiO2/Si interface caused by CO adsorption are discussed in terms of the surface photovoltage effect and work function variation.

Sign in / Sign up

Export Citation Format

Share Document