Catalytic performance of montmorillonite clay ion-exchanged with ionic liquids in the cycloaddition of carbon dioxide to allyl glycidyl ether

In this study, various ionic liquids immobilized onto montmorillonite clay (IL-MMT) were prepared by ion-exchange reaction between the ionic liquids and ions in the clay interlayer. Tetra-alkyl ammonium chlorides were used as the ionic liquid precursors. The IL-MMTs were characterized by elemental analyses (EA), BET, XRD, 13C NMR, FT-IR, and SEM. The surface areas and d-spacings of the IL-MMTs increased with increasing alkyl chain lengths. The IL-MMTs showed good catalytic activity for the synthesis of the cyclic carbonate from alkyl glycidyl ether (AGE) and carbon dioxide. The effects of the IL cation structure, and reaction parameters such as temperature and CO2 pressure on the reactivity of IL-MMTs were also discussed. The catalyst could be reused in up to four consecutive runs without a significant reduction in the initial activity.

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► Montmorillonite (MMT) clay was ion-exchanged with ionic liquids (IL).
► Higher surface area and d-spacing are obtained with longer alkyl chain length.
► IL-MMTs showed good catalytic performance for the synthesis of cyclic carbonate.
► The catalysts could be reused four times without any significant activity loss.