Encapsulated Lewis acidic ionic liquids by halloysite using as efficient catalyst for CO2 conversion

A type of clay-supported catalysts were developed for conversion of CO 2 by encapsulating ZnBr 2 -based Lewis acidic ionic liquids (ZnBr 2 /IL) in halloysite (Hal) via a one-step strategy. The Lewis acidic ionic liquid was loaded within enlarged lumens of Hal via acid treatment, and the mesoporous structure was found to benefit for CO 2 storage/conversion. The composite ZnBr 2 /IL@P-Hal was found to have an adsorption capacity (6.43 cm 3 /g) of CO 2 via adsorption/desorption isotherm measurements. The composite ZnBr 2 /IL@P-Hal showed excellent catalytic performance (TOF value was 1747.7 h −1 ) for coupling of CO 2 with epoxides to produce propylene carbonate under the lack of any cocatalyst . Kinetic investigations indicated the reaction followed an order of one, with respect to catalyst ZnBr 2 /IL@P-Hal. The overall pathway of CO 2 cycloaddition was theoretically validated via DFT calculations. These experimental and computational efforts deepen comprehension of the rational design of clay-based catalysts for CO 2 cycloaddition, further elucidated halloysite was a promising support. • Halloysite was encapsulated with Lewis acidic ionic liquids and ZnBr 2 . • The lumen of halloysite was enlarged to load ionic liquids. • Better adsorption of CO 2 and excellent catalytic performance were obtained. • DFT was done to reveal the pathway of CO 2 cycloaddition.