The co-adsorption of H2O and NO2 molecules on a well-ordered, ultrathin ?-Al2O3/NiAl(100) film surface was studied using temperature programmed desorption (TPD), infrared reflection absorption spectroscopy (IRAS) and X-ray photoelectron spectroscopy (XPS). For H2O and NO2 monolayers adsorbed separately on the ?-Al2O3/NiAl(100) surface, adsorption energies were estimated to be 44.8 kJ/mol and 36.6 kJ/mol, respectively. Coadsorption systems prepared by sequential deposition of NO2 and H2O revealed the existence of coverage and temperature dependent adsorption regimes where H2O molecules and the surface NOx species (NO2/N2O4/NO2-,NO3-) form segregated and/or mixed domains. Influence of the changes in the crystallinity of solid water (amorphous vs. crystalline) on the coadsorption properties of the NO2/H2O/?-Al2O3/NiAl(100) system is also discussed.
Revised: May 16, 2006 |
Published: April 20, 2006
Citation
Ozensoy E., C.H. Peden, and J. Szanyi. 2006.Low Temperature H2O and NO2 Coadsorption on ?-Al2O3/NiAl(100) ultrathin films.Journal of Physical Chemistry B 110, no. 15:8025-8034.PNNL-SA-47854.doi:10.1021/jp057534c