Chapter 9 - Palladium Complexes and Nanoparticles Encapsulated by Functionalized Mesoporous Silica Materials: A Promising Hybrid Catalyst in Organic Transformations

Abstract

Nowadays, mesoporous silica (MS) materials have been considered good candidates for supporting and generating metal nanoparticles (NPs) inside their pores, owing to their high surface area, good stability, and tunable pore sizes. Encapsulation not only preserves and stabilizes metal NPs during the catalysis, it makes MS a nanoreactor in which the reactants diffuse and react inside within the cavities. This approach has brought an opportunity to make a new and advanced of catalysts for various types of reactions such as cross-couplings and photocatalytic and redox reactions. Among metal NPs, palladium NPs are very important thanks to the diverse catalytic ability of Pd in various reactions. In recent years, various types of modifications have been designed for the encapsulation of Pd catalytic species inside the porosity of mesopores. These modifications that can be performed by organic groups leads to the production of a hybrid inorganic-organic encapsulating agent for Pd NPs. Herein, the types and mechanisms of modifications on the surface of MS nanomaterials and their incorporation in the encapsulation of Pd NPs are overviewed. Moreover, the catalytic utility of encapsulated Pd species in the organic transformations is discussed.