D2O TPD spectra adsorbed on the hydrogen pre-adsorbed Rh(111) surfaces as a function of the hydrogen coverage θ(H). (a) θ(H) = 0, (b) θ(H) = 0.39, (c) θ(H) = 0.74, (d) θ(H) = 1.0 [The coverage of hydrogen atoms is described by fractional coverage θ(H)]. Water molecules were adsorbed at 135 K followed by TPD measurements. The coverage of water molecules is described by fractional coverage θ(D2O) estimated using TPD: θ(D2O) = 1.0 is defined as the saturation of the first layer. The sample was heated with a linear temperature ramp of 1.3 K/s.
IRAS spectra of D2O [θ(D2O) ∼ 1.0] adsorbed on the hydrogen pre-adsorbed Rh(111) surfaces as a function of the hydrogen coverage θ(H). Water molecules were adsorbed at 135 K followed by IRAS measurements at 20 K.
(a) Xe TPD spectra for ∼1 ML Xe deposited on H/Rh(111) (lower curve) and D2O/H/Rh(111) (upper curve), where θ(H) = 1.0 and θ(D2O) = 40.3. The temperature (K) vs. time (s) relation is illustrated as a dotted curve. (b) Xe TPD spectra post-dosed on the D2O/H/Rh(111) surface. (c) Fractional coverage of Xe adsorbed on a bare surface area (filled circles) and average thickness (open circles) as a function of water coverage θ(D2O). (d) Fractional bare area versus θ(D2O)2/3. The line is a linear fit to the data.
D2O coverage on Rh(111) and H/Rh(111) [θ(H) = 1.0] as a function of D2O exposure. The substrate temperature during adsorption was 135 K. The dashed and solid lines are the fitted results.
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