AVS 54th International Symposium | |
Surface Science | Monday Sessions |
Session SS1-MoA |
Session: | Water-Surface Interactions |
Presenter: | P. Uvdal, Lund University, Sweden |
Authors: | P. Uvdal, Lund University, Sweden J. Blomquist, Lund University, Sweden |
Correspondent: | Click to Email |
Proton transfer in water through the reaction H2O + D2O -> 2HDO is one of many intriguing properties of water. We have studied the exchange in water at ice surfaces and on a Cu(100) surface using infrared vibrational spectroscopy. Intact molecules of H2O and D2O are observed up on adsorption at 84 K and no H/D exchange is observed in H2O/D2O mixtures . By monitoring the O-H (3695 cm-1) and O-D (2730 cm-1) stretches assigned to none-hydrogen bonded water molecules at the surface of the ice we have followed the H/D exchange in the temperature region 84 - 145 K. A clear isotope effect is observed in 4/1 mixtures of H2O/D2O or D2O/H2O. The majority isotope governs the exchange efficiency. The exchange is completed at 140 K resulting in at total scrambling of the isotopes. The vibrational data is interpreted with the aide of DFT calculations of small water complexes.