Liquid-phase synthesis of nanocatalysts
Résumé
The rational design of new catalyst needs a trustworthy toolbox of processes allowing nano-level control of key characteristics as composition, crystallographic structure, dimensions, architectures, and interfaces. In this toolbox, liquid-phase syntheses benefit from a rather long history in precipitation, with many thermodynamic and kinetic data available for chemical engineers. Liquid-phase processes offer a compromise between industrial constraints and fine control of nanostructures. This chapter focuses on two families of materials - metallic oxides and metals - and shows by selected examples how they can be shaped and interfaced at the nanoscale using simple and industrially relevant processes to create nanocatalysts. The size reduction of metallic particles to the nanolevel induces geometrical and electronic effects, both playing a role in their catalytic properties. Well-faceted polyhedral metallic nanoparticles have a significant fraction of atoms not only on crystal faces but also on edges or even corners, sites that are likely favorable to high catalytic activity.