Immobilized Ionic Liquids In Layered Compounds Via Mechanochemical Intercalation As Catalysts for CO2 Fixation

A facile mechanochemical intercalation approach was adopted to immobilize 1-butyl-3-methylimidazolium chloride (BMIMCl) in layered α-zirconium phosphate (ZrP). The intercalation compounds with expanded layer distance were confirmed by X-ray diffraction. Thermogravimetric characterization revealed that partial BMIMCl was intercalated into the ZrP galleries, while partial was adsorbed on the layer surface. The immobilized BMIMCl was evaluated for catalysis evaluation of the coupling reaction of CO₂ and propylene oxide to synthesize propylene carbonate. The immobilized BMIMCl exhibited close reactivity as free BMIMCl. Overall, the mechanochemical approach proves to be effective to immobilize ionic liquids in layered compounds, and thus may expand the applications of ionic liquids, and meanwhile improve catalyst separation and recycling.