Toward the synthesis of cyclic carbonate by chemical fixation of carbon dioxide onto epoxides, a kinetic study by Raman spectroscopy under pressure

Due to concerns about global warming together with the decrease of fossil resources, the chemical transformation of carbon dioxide into added-value products has gained interest. Even though carbon dioxide is a thermodynamically and kinetically stable molecules, it can react with basic compounds, strong nucleophiles, olefins, alkynes or alcohols using appropriate catalysts. To date, the chemical fixation of CO2 onto epoxides is of the most promising way to valorize carbon dioxide at an industrial scale. Indeed, cyclic carbonates are useful as intermediates for polycarbonates and polyurethanes, electrolytes in lithium ion batteries, or green solvents. Although fixation of carbon dioxide onto epoxides has been extensively studied, the design of highly effective catalysts still remains a challenge as well as the development of online analytical tools allowing the measurement under pressure of the real time conversion of epoxides into cyclic carbonates. We therefore report on the use of a simple experimental device that combines a high pressure cell equipped with a sapphire window and a mobile probe connected to a Raman spectrometer, for the real time monitoring of the chemical fixation of CO2 onto poly(ethyleneglycol) diglycidyl ether using organic catalysts and for the estimation of the kinetic constant.