Imidazolium-based silica microreactors for the efficient conversion of carbon dioxide

Abstract

Imidazolium-based silica microreactors were synthesized by a one-pot procedure. A straightforward synthesis approach was achieved through self-organization/polymerization of the amphipathic organic salts that behave as templates for the construction of silica architecture and as catalytic active sites. The porous silica shell allowed the diffusion of reactants and products to/from the active sites and conferred stability to the polymeric matrix. The solid was extensively characterised by transmission and scanning electron microscopy, N₂ adsorption/desorption, X-ray diffraction, ²⁹Si solid-state MAS-NMR and combustion chemical analysis. The material was tested as a catalyst for the reaction of carbon dioxide with various epoxides to produce cyclic carbonates. The organic–inorganic hybrid microreactors displayed excellent performance in terms of both yield and selectivity. Moreover, it can be used in multiple catalytic cycles.