Chemical fixation of CO2 to ethylene carbonate under supercritical conditions:: continuous and selective

Chemical fixation of CO2 to ethylene carbonate proceeds effectively under supercritical conditions by using as catalyst the system cf an immobilized cobalt complex in conjunction with a quaternary ammonium salt in a flow apparatus, based on supercritical fluid used as both a solvent and a reactant for continuous synthesis of organic compound. A conversion of up to 85.6% for ethylene oxide was achieved at 110 degreesC and 12.5 MPa, which value is about 4.5 times that under subcritical condition (4.0 MPa). No byproduct such as polycarbonates or polyester was observed in the obtained products. The immobilized cobalt complex exhibited good stability and was subjected to utilization for 24 h with no loss of activity. The powder X-ray diffraction patterns indicate no change in the structure of the supported mesoporous silica during the reaction. (C) 2004 Elsevier B.V. All rights reserved.