Capping agents (organic ligands, polymers, surfactants, etc.) are a basic component in the synthesis of metal nanoparticles with controlled size and well-defined shape. However, their influence on the performances of nanoparticle-based catalysts is multifaceted and controversial. Indeed, capping agent can act as a “poison”, limiting the accessibility of active sites, as well as a “promoter”, producing improved yields and unpredicted selectivity control. These effects can be ascribed to the creation of a metal-ligand interphase, whose unique properties are responsible for the catalytic behavior. Therefore, understanding the structure of this interphase is of prime interest for the optimization of tailored nanocatalyst design. This review provides an overview of the interfacial key features affecting the catalytic performances and details a selection of related literature examples. Furthermore, we highlight critical points necessary for the design of highly selective and active catalysts with surface and interphase control.

The use of heterogeneous catalytic systems for the development of low environmental impact processes has led to an enlargement of studies in this field, especially in order to optimize the selectivity of the reactions. This contribution aims to provide an overview of the role of the supporting materials in determining the activity/selectivity of the catalytic material and to highlight the perspective possibilities of modifying the surface or bulk properties of the support in order to optimize the catalytic performances.