TY - JOUR
T1 - Adsorption of H2O on oxidized Fe(100) surfaces
T2 - comparison between the oxidation of iron by H2O and O2
AU - Hung, W. H.
AU - Schwartz, J.
AU - Bernasek, S. L.
N1 - Funding Information:
This work was partially supportedb y the National ScienceF oundation,C HE-923991.
PY - 1993/9/1
Y1 - 1993/9/1
N2 - The adsorption and reaction of water on the preoxidized Fe(100) surface is studied using LEED, AES, thermal desorption and high resolution EELS. Oxidation of the Fe(100) surface by water adsorption results in a disordered c(2 × 2) surface, with a saturation oxygen coverage of 0.39 ML. This surface cannot be further oxidized by exposure to water, but can be further oxidized by molecular oxygen. When water is adsorbed on the submonolayer oxygen pre-exposed surface, hydrogen transfer from water to adsorbed atomic oxygen occurs, forming a hydroxyl group. This group migrates from the fourfold hollow site, where it is formed, to the bridge site on this surface. Adsorbed oxygen facilitates water decomposition via this hydrogen transfer process. On the oxygen precovered surface with an oxygen coverage of 1 ML (p(1 × 1)O surface), water adsorbs molecularly and desorbs at 175 K without decomposition.
AB - The adsorption and reaction of water on the preoxidized Fe(100) surface is studied using LEED, AES, thermal desorption and high resolution EELS. Oxidation of the Fe(100) surface by water adsorption results in a disordered c(2 × 2) surface, with a saturation oxygen coverage of 0.39 ML. This surface cannot be further oxidized by exposure to water, but can be further oxidized by molecular oxygen. When water is adsorbed on the submonolayer oxygen pre-exposed surface, hydrogen transfer from water to adsorbed atomic oxygen occurs, forming a hydroxyl group. This group migrates from the fourfold hollow site, where it is formed, to the bridge site on this surface. Adsorbed oxygen facilitates water decomposition via this hydrogen transfer process. On the oxygen precovered surface with an oxygen coverage of 1 ML (p(1 × 1)O surface), water adsorbs molecularly and desorbs at 175 K without decomposition.
UR - http://www.scopus.com/inward/record.url?scp=0027657533&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027657533&partnerID=8YFLogxK
U2 - 10.1016/0039-6028(93)90155-D
DO - 10.1016/0039-6028(93)90155-D
M3 - Article
AN - SCOPUS:0027657533
SN - 0039-6028
VL - 294
SP - 21
EP - 32
JO - Surface Science
JF - Surface Science
IS - 1-2
ER -