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.
On the Impact of Solvation on a Au/TiO2 Nanocatalyst in Contact with Water
Camellone Matteo Farnesi;
2013
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
