The conversion of carbon dioxide into valuable chemicals such as cyclic carbonates is an appealing topic for the scientific community due to the possibility of valorizing waste into an inexpensive, available, nontoxic, and renewable carbon feedstock. In this regard, last-generation heterogeneous catalysts are of great interest owing to their high catalytic activity, robustness, and easy recovery and recycling. In the present review, recent advances on CO₂ cycloaddition to epoxide mediated by hybrid catalysts through organometallic or organo-catalytic species supported onto silica-, nanocarbon-, and metal–organic framework (MOF)-based heterogeneous materials, are highlighted and discussed.

Multilayered covalently supported ionic liquid catalysts achieve excellent TON and productivity in the reaction of CO₂ with various epoxides to produce cyclic carbonates.

Polyhedral oligomeric silsesquioxanes (POSS) are organic–inorganic hybrid molecules piquing the interest of researchers thanks to their synergistic features. The great versatility of POSS nanostructures arises from the easy tunability of peripheral organic moieties combined with the high thermal and chemical stability of the inner inorganic core. In this review, we highlight the use of POSS nanostructures as molecular precursors for the synthesis of homogeneous and heterogeneous catalysts able to promote many processes including alkene epoxidation, C–C bond formation, CO₂ conversion, “click reactions”, hydrogenation, and ethylene polymerisation, among others. In this scenario, POSS units found application as molecular models for single-site heterogeneous catalysts, stabilising platforms for metal nanoparticles, metal ligands, supports for organic salts, and molecular building blocks for the design of ionic polymers. Herein, we address the catalytic application of POSS nanostructures with the purpose of encouraging the development of performing hybrid catalysts with tailored properties.

Polyhedral oligomeric silsesquioxane functionalized with imidazolium chloride peripheries was synthesized and successfully used as a catalyst for CO ₂ conversion.