title: Water Interaction with Iron Oxides.
abstract: We present a mechanistic study on the interaction of water with a well-defined model Fe3O4(111) surface that was investigated by a combination of direct calorimetric measurements of adsorption energies, infrared vibrational spectroscopy, and calculations bases on density functional theory (DFT). We show that the adsorption energy of water (101 kJ mol(-1)) is considerably higher than all previously reported values obtained by indirect desorption-based methods. By employing (18)O-labeled water molecules and an Fe3 O4 substrate, we proved that the generally accepted simple model of water dissociation to form two individual OH groups per water molecule is not correct. DFT calculations suggest formation of a dimer, which consists of one water molecule dissociated into two OH groups and another non-dissociated water molecule creating a thermodynamically very stable dimer-like complex.
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Petr
authors.initials: P
authors.lastname: Dementyev
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Dostert
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Francisco
authors.initials: F
authors.lastname: Ivars-Barceló
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Casey P
authors.initials: CP
authors.lastname: O'Brien
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Francesca
authors.initials: F
authors.lastname: Mirabella
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany). schauermann@fhi-berlin.mpg.de.|Institute of Physical Chemistry, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Str. 2, 24118 Kiel (Germany). schauermann@fhi-berlin.mpg.de.
authors.forename: Swetlana
authors.initials: S
authors.lastname: Schauermann
authors.affiliation: Institut für Chemie, Humboldt-Universität, Unter den Linden 6, 10099 Berlin (Germany).
authors.forename: Xiaoke
authors.initials: X
authors.lastname: Li
authors.affiliation: Institut für Chemie, Humboldt-Universität, Unter den Linden 6, 10099 Berlin (Germany). joachim.paier@chemie.hu-berlin.de.
authors.forename: Joachim
authors.initials: J
authors.lastname: Paier
authors.affiliation: Institut für Chemie, Humboldt-Universität, Unter den Linden 6, 10099 Berlin (Germany).
authors.forename: Joachim
authors.initials: J
authors.lastname: Sauer
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin (Germany).
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Freund
keywords: calorimetry; density functional calculations; infrared spectroscopy; surface science; water adsorption