Ammonia adsorption by hydrogen bond on ice and its solvation

Regarding the solvation of molecules to water, the adsorption of molecules on the water surface has mostly been considered. Here we provide spectroscopic evidence for the adsorption and solvation behavior of ammonia on the ultra thin ice film surface formed on Ru(001) by the use of infrared reflection absorption and thermal desorption spectroscopies. Here we prove that the solvation of ammonia involves two steps. They are the hydrogen bond adsorption and the transfer into bulk. The hydrogen bonding adsorbed ammonia on ultra thin ice film in a ${\mathrm{NH}}_3$ form is evidenced for the first time. Upon heating, bulk transfer upon a conversion to a ${\mathrm{NH}}_4^{+}$ form is observed for this hydrogen bonded species, however it is not for bilayer and multilayer species. © 2000 American Institute of Physics.