Rational screening of deep eutectic solvents for the removal of halogenated volatile organic compounds

Abstract

A novel screening method integrating theoretical calculations with experimental validation was proposed to select deep eutectic solvents (DESs) for the highly efficient removal of halogenated volatile organic compounds (HVOCs) from exhaust gas. 1,2-Dichloroethane and dibromomethane were used to evaluate the reliability of this screening method. Following a meticulous screening process, tetraethylammonium chloride (TEAC) and levulinic acid (Lev) were identified as the hydrogen bond acceptor and donor, respectively, for the preparation of the DES TEAC–Lev (1:2). The TEAC–Lev (1:2) exhibited favorable viscosity and thermal stability, ensuring its outstanding recyclability over multiple absorption–desorption cycles. The absorption ratios of 1,2-dichloroethane and dibromomethane using the prepared DESs were both greater than 98.5%. The microscopic absorption mechanism indicates that the excellent absorption performance of TEAC–Lev (1:2) is mainly attributed to hydrogen bond interactions between the chlorine atoms and HVOCs, as well as between Lev and HVOCs.