Imidazole based ionic liquid grafted graphene for enhancing the new green conversion process of carbon dioxide

Abstract

Carbon dioxide (CO2) has been recognized a renewable C1-level green chemical synthesis feedstock. Achieving 100 % atom utilization is possible through the cycloaddition reaction of CO2 with epoxides. Ionic liquids are commonly used catalysts for this reaction, but conventional immobilization methods may lead to the loss of active components under severe conditions. Developing a new Ionic Liquid catalytic system offers a promising and eco-friendly approach to efficient CO2 cycloaddition. In this study, imidazolium ionic liquid was chemically immobilized on graphene oxide (GO) to get a novelty catalyst GO-SmIm Br. The impact of catalyst dosage, temperature, pressure, and reaction time on the reaction performance of CO2 and propylene oxide was systematically investigated in a batch reaction system, achieving a propylene carbonate yield of up to 90.4 % in the CO2 cycloaddition reaction. Even after five cycles, the yield only decreased by 9.6 %, showcasing its robust catalytic activity. Further assessment in a fixed-bed reactor at 120 °C for 8 h demonstrated a continuous propylene carbonate yield of 55.6 %, highlighting the potential of GO-SmIm Br for efficient and sustainable CO2 utilization.