One-Pot Synthesis of Styrene Carbonate from Styrene and CO2 Over the Nanogold-Ionic Liquid Catalyst

A catalyst system for the efficient two-step coupling of CO2 and styrene to styrene carbonate was developed. Gold nanoparticles immobilized on multi-walled carbon nanotubes (Au/CNT) of 6 nm in diameter were used as a catalyst for the epoxidation step. The process was carried out at 80 A degrees C for 4 h in the presence of anhydrous tert-butyl hydroperoxide as an oxidant. The reaction of the resulting epoxide and CO2 was catalyzed by the 1-butyl-3-methylimidazolium bromide [bmim]Br-ZnBr2 system under the CO2 pressure (1.2 MPa) at 120 A degrees C. A high styrene carbonate yield of 60 % was achieved. After the reaction, Au/CNT could be easily separated and reused without any significant loss of activity.