Highly efficient and recyclable conversion of CO2 using supported metal-free ionic liquids on ball clay

A type of clay-supported catalysts was developed for cycloaddition of CO2 by immobilizing metal-free ionic liquids (IL) on ball clay (BC) via a one-step strategy. The metal-free IL was loaded on the surface of BC via thermal and acid treatment. The synthesized materials (IL@P-BC) were characterized by Fourier transform infrared spectroscopy (FTIR), N-2 adsorption-desorption, and transmission electron microscopy (TEM). The composite IL@P-BC demonstrated excellent catalytic performance (yield 94.0%, selectively >99%) for coupling of CO2 with epoxides to produce cyclic carbonates under the lack of any co-catalyst. The good recyclability and excellent suitability were obtained for the composite IL@P-BC. These experimental analyses deepen comprehension of the rational design of clay-based catalysts for CO2 cycloaddition, further confirmed ball clay was a promising support.