The solvation of sodium ions in water clusters: intermolecular potentials for Na⁺-H₂O and H₂O-H₂O

Abstract

New model potentials are constructed for Na + H~O and H20-H20, using quantum mechanical calculations of the monomer wavefunctions. One parameter in each model potential is fitted to experimental dimer properties. The resulting Na+-H20 potential is consistent with published thermodynamic and ab initio data, and the H~O-H20 potential reproduces the structure and energy of the water dimer at equilibrium, and the second virial coefficient of steam, within experimental uncertainties. The donor-acceptor interchange tunnelling pathway on the water dimer potential energy surface has a lower energy barrier than the acceptor-acceptor interchange, in agreement with recent spectroscopic studies. When a simple non-additive induction potential is included, calculated thermodynamic properties of solvated sodium ions are in agreement with experimental data. For small clusters in the gas phase, the first solvation shell of the sodium ion is predicted to contain four water molecules.

Effect of a Physisorbed Tetrabutylammonium Cation Film on Alkaline Hydrogen Evolution Reaction on Pt Single-Crystal Electrodes

“…In fact, it has been shown that the hydrophobicity of these cations effectively impedes the irreversible oxidation and surface roughening of Pt(111) electrocatalysts during oxide formation and reduction processes in alkaline media by inhibiting the formation of OH ads /O ads (H 2 O) on the surface . On the other hand, Na + establishes stronger interactions with H 2 O in its solvation shell than TBA + . , Different interactions with H 2 O could alter the state of the OH ads adlayer on Pt(111). Importantly, these results show that at these low concentrations, TBA + does certainly interact with the surface, although this is not visible from the H UPD region.…”

“… 38 On the other hand, Na + establishes stronger interactions with H 2 O in its solvation shell than TBA + . 27 , 39 Different interactions with H 2 O could alter the state of the OH ads adlayer on Pt(111). Importantly, these results show that at these low concentrations, TBA + does certainly interact with the surface, although this is not visible from the H UPD region.…”