On the Impact of Solvation on a Au/TiO2 Nanocatalyst in Contact with Water

TL;DR

This study uses ab initio simulations to reveal how water influences charge states and reactivity of a gold nanocatalyst on titania, highlighting solvent effects on catalytic activity.

Contribution

It provides detailed microscopic insights into solvent-induced charge rearrangements and the formation of active sites on a Au/TiO2 catalyst in water, a novel understanding for liquid-phase catalysis.

Findings

Water stabilizes charge states differently than in gas phase.

Solvent induces both cationic and anionic solvation of the metal cluster.

Solvent effects create new active sites on the catalyst.

Abstract

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.