Rapid and effective cycloaddition of environmentally diluted CO2 catalyzed by hierarchical porous ionic carbon at atmospheric conditions

Abstract

From the perspective of environmental protection and sustainable development, the strategy of directly converting CO2 into high value-added chemicals is extremely strategic but still presents challenges in terms of efficient conversion of waste and diluted CO2. In this work, based on multilayer carbon materials, we prepared a variety of hierarchical porous ionic materials rich in ionic groups by introducing self-polymerizing functionalized positive charged delocalized ILs. These materials are utilized as recyclable heterogeneous catalysts for cycloaddition reactions between various epoxides and pure/dilute CO2 under mild conditions. Further research has revealed that the superior performance is attributed to the interesting synergistic effects, including hierarchical porous carbon frameworks, linear multi-nitrogen flexible ILs moieties as hydrogen bond donors (HBDs), and easy to leave halogen anions as nucleophiles. Furthermore, the results of XPS spectra and density functional theory (DFT) calculations suggest that positive charged delocalized ILs accelerate the reaction by providing strong hydrogen bonding effects and enhancing the nucleophilicity of halide anions. Moreover, it is found that the catalyst could maintain its activity after 5 cycles of experiments, which has a good application prospect.