Hierarchical porous silica monoliths: A novel class of microreactors for process intensification in catalysis and adsorption

Abstract

Silica monoliths with hierarchical porosity (macro-/mesoporous), prepared by a combination of phase separation (spinodal decomposition) and sol–gel process, have demonstrated remarkable potential as supports for catalysts and adsorbents with improved efficiency and productivity of a number of applications. This is due to perfect homogeneous interconnected porous networks enabling an exceptional mass transfer and a fine control of contact times. Silica monoliths have been functionalized by an important variety of moities and techniques, such as grafting with versatile species (acidic, basic), by alumina coating, immobilization of ionic liquids, in-situ synthesis of nanoparticles of Pd, MOF, and NiMoS 2 , pseudomorphic transformation of the skeleton into MCM-41 or zeolites (SOD, LTA). These functional materials reveal great opportunities for process intensification.