  Water, the ubiquitous solvent, is also prominent in forming liquid solid
interfaces with catalytically active surfaces, in particular with promoted
oxides. We study the complex interface of a gold nanocatalyst, pinned by an F
center on titania support, and water. The ab initio simulations uncover the
microscopic details of solvent-induced charge rearrangements at the metal
particle. Water is found to stabilize charge states differently from the gas
phase as a result of structure specific charge transfer from to the solvent,
thus altering surface reactivity. The metal cluster is shown to feature both
cationic and anionic solvation, depending on fluctuation and polarization
effects in the liquid, which creates novel active sites. These observations
open up an avenue toward solvent engineering in liquid-phase heterogeneous
catalysis.
