Vacancy-cluster-mediated surface activation for boosting CO2 chemical fixation.

Abstract

The cycloaddition of CO2 with epoxides towards cyclic carbonates provides a promising pathway for CO2 utilization. Given the crucial role of epoxide ring opening in determining the reaction rate, designing catalysts with rich active sites for boosting epoxide adsorption and C-O bond cleavage is necessary for gaining efficient cyclic carbonate generation. Herein, by taking two-dimensional FeOCl as a model, we propose the construction of electron-donor and -acceptor units within a confined region via vacancy-cluster engineering to boost epoxide ring opening. By combing theoretical simulations and in situ diffuse reflectance infrared Fourier-transform spectroscopy, we show that the introduction of Fe-Cl vacancy clusters can activate the inert halogen-terminated surface and provide reactive sites containing electron-donor and -acceptor units, leading to strengthened epoxide adsorption and promoted C-O bond cleavage. Benefiting from these, FeOCl nanosheets with Fe-Cl vacancy clusters exhibit enhanced cyclic carbonate generation from CO2 cycloaddition with epoxides.