Stability of water monolayers on Ru(0 0 0 1): Thermal and electronically induced dissociation

• Published in: Chemical physics letters Vol. 415; no. 1; pp. 165 - 171
• Main Authors: Faradzhev, N.S., Kostov, K.L., Feulner, P., Madey, T.E., Menzel, D.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 24.10.2005
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2005.08.119

To clarify conflicting reports on the composition and stability of H 2O and D 2O adsorbates on Ru(0 0 0 1), we have conducted correlated experiments in two laboratories using X-ray photoelectron spectroscopy and thermal desorption spectroscopy, without and after controlled electron irradiation. Both species form molecular wetting layers; D 2O stays molecular to desorption while H 2O undergoes a thermal conversion that has been interpreted as partial dissociation. Electron impact leads to this conversion for both H 2O and D 2O with very high cross-sections (in the high 10 −16 cm 2 range at 100–200 eV) and low threshold energies. These effects may explain discrepancies in recent reports.