Proton transfer in adsorbed water dimers

Abstract

Density functional theory simulations of water on MgO(001) reveal rapid proton transfer within clusters of just two water molecules. Facile dissociation and recombination of the molecules within the dimers along with a concerted surface-mediated exchange of protons between water and hydroxyl molecules makes this possible. We suggest that surface-mediated proton transfer is in general likely to lead to proton transfer in interfacial water systems whenever the relative energies of intact and dissociated states of water are similar.