A promising new strategy for immobilizing a water-soluble oligomeric ionic liquid by coating the ionic liquid with mesoporous silica was established. The immobilized ionic liquid (IL@SiO2) exhibited a good catalytic activity for the production of cyclic carbonates through the cycloaddition of different epoxides with CO2 under solvent-free conditions. The IL@SiO2 catalyst was characterized by different techniques such as FTIR spectroscopy, XRD, TG analysis, FESEM-EDX spectroscopy, map analysis, BET analysis, and TEM. Use of 30 mg of the IL@SiO2 catalyst, which contained 0.023 mmol of the oligomeric ionic liquid IL-3, resulted in a yield of cyclic carbonate with styrene oxide of greater than 95% and a selectivity to the cyclocarbonate of almost 100%. We realized that the hydroxyl groups on the surface of silica could play an important role in the reaction through the hydrogen bonding interactions between the epoxides and the hydroxyl groups. Moreover, the prepared catalyst was very stable under the reaction conditions and reusable for at least five runs without a considerable change in the yield of the reaction. The effects on the formation of cyclic carbonates of different factors, such as pressure, time, amount of catalyst, and temperature, were investigated.