Schematic showing the structure of the mixed layer (Refs. 26, 27, and 40) (top) and a hypothetical commensurate water layer on Pt(111) (Ref. 15) (bottom). The mixed structure has O coplanar, whereas the water structure is buckled into a bilayer, with alternate waters bonded to Pt via O and linked by hydrogen bonds to water in the upper half of the bilayer. The upper layer is shown (arbitrarily) with the uncoordinated H atoms pointing into the vacuum.
Desorption of a submonolayer dose of chloroform on top of (a) pure crystalline ice and (b) water adsorbed on the mixed layer. The ice films were formed by adsorption at .
Comparison of chloroform desorption from ice films of different thicknesses prepared by desorption of an 80 ML film at (solid dark lines) with ice films of similar coverage formed by growth at (broken lines).
Comparison of the morphology of ice multilayers of different thicknesses as determined by chloroform TPD. Solid symbols and lines are for ice films grown at and the open symbols and dashed lines for films formed by desorption of an 80 layer ASW film at . The relative intensity of the chloroform peaks has been normalized to 1 and the lines are drawn to guide the eye. (a) Clean Pt(111) showing the signal due to the monolayer (, , and peaks), multilayer ( peak) and pores ( peak). (b) Adsorption on the structure showing the signal due to the monolayer ( and peaks). The solid triangles show the disappearance of the monolayer during ASW growth at .
(a) Morphology of the ice surface following growth of 5 ML ice at different temperatures showing the intensity of the chloroform features associated with different structures. (b) Water TPD traces for 5 ML ice as a function of the growth temperature. Desorption is stabilized by formation of large clusters when the ice film is grown at higher temperatures.
Thermal desorption of 3 ML of water from clean Pt(111) (dashed line) and from a mixed layer containing different amounts of OH. Heating rate is .
(a) Isothermal desorption of 32 ML of water from clean Pt(111) and a Pt(111) layer at . (b) The lower frame shows the effect of varying the thickness of ice adsorbed on the structure on the isothermal desorption traces.
DFT structures for water adsorbed on top of the structure. (a) a commensurate layer, (b) water on top of an layer with 25% excess water replacing OH, and (c) a hexamer adsorbed on the structure.
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