TY - JOUR
T1 - The effects of carbon, oxygen, sulfur and potassium adlayers on CO and H2 adsorption on Fe(100)
AU - Benziger, Jay Burton
AU - Madix, R. J.
N1 - Funding Information:
The authors gratefully acknowledget he support of the National Science Foundation through grant NSF Eng 77-12964 throughout the course of this work. Support from equipment grant NSF Eng 75-14191 is also gratefully acknowledged without which this work could not have been accomplished. We also wish to expresso ur appreciation to Professor WA. Harrison for assistancew ith the LCAO calculations.
PY - 1980/4/1
Y1 - 1980/4/1
N2 - The adsorption and desorption of CO and hydrogen was studied on clean Fe(100) and Fe(100) with adiayers of carbon, oxygen, sulfur, and potassium using X-ray photoelectron spectroscopy (XPS), and temperature programmed desorption. Hydrogen was found to be dissociatively adsorbed on Fe(100) with a binding energy of 86 kJ/mole. CO absorption was found to be complex, involving several molecular binding states as well as dissociated CO. The activation energy for dissociation of CO on Fe(100) was estimated to be 105 kJ/mole. Sulfur, oxygen, and carbon adlayers all reduced the binding energies for CO and hydrogen and inhibited CO dissociation. Potassium was observed to enhance the CO and hydrogen binding strengths and increase the amount of CO dissociation relative to the clean surface. These results have been compared to LCAO calculations for CO adsorption on an Fe(100) surface with adiayers. The model calculations showed that adiayers of carbon, oxygen, and sulfur reduced the CO binding energy on Fe(100) by bonding with the same Fe(3d) orbitals as the CO(2π*) orbitals would. Potassium was found to enhance the CO binding energy on Fe(100) due to interactions between the K(4s) orbital and the CO(2π*) orbitals.
AB - The adsorption and desorption of CO and hydrogen was studied on clean Fe(100) and Fe(100) with adiayers of carbon, oxygen, sulfur, and potassium using X-ray photoelectron spectroscopy (XPS), and temperature programmed desorption. Hydrogen was found to be dissociatively adsorbed on Fe(100) with a binding energy of 86 kJ/mole. CO absorption was found to be complex, involving several molecular binding states as well as dissociated CO. The activation energy for dissociation of CO on Fe(100) was estimated to be 105 kJ/mole. Sulfur, oxygen, and carbon adlayers all reduced the binding energies for CO and hydrogen and inhibited CO dissociation. Potassium was observed to enhance the CO and hydrogen binding strengths and increase the amount of CO dissociation relative to the clean surface. These results have been compared to LCAO calculations for CO adsorption on an Fe(100) surface with adiayers. The model calculations showed that adiayers of carbon, oxygen, and sulfur reduced the CO binding energy on Fe(100) by bonding with the same Fe(3d) orbitals as the CO(2π*) orbitals would. Potassium was found to enhance the CO binding energy on Fe(100) due to interactions between the K(4s) orbital and the CO(2π*) orbitals.
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U2 - 10.1016/0039-6028(80)90160-0
DO - 10.1016/0039-6028(80)90160-0
M3 - Article
AN - SCOPUS:48849085017
SN - 0039-6028
VL - 94
SP - 119
EP - 153
JO - Surface Science
JF - Surface Science
IS - 1
ER -