Synergistic effect of hydrogen bond donors in deep eutectic solvents on separation of dimethyl carbonate/ethanol

Abstract Deep eutectic solvents (DESs) have been widely concerned in recent years. This study focused on the designability of DES and used COSMO‐RS to screen DES, preparing five DESs, including two dual hydrogen‐bond donor (HBD) DESs. Five kinds of DESs were characterized, the effects of different HBD combinations on the physical properties of DESs were studied, and vapor–liquid phase equilibrium experiments were conducted to study the thermodynamic phase behavior of the system. The results demonstrated that the dual hydrogen‐bond donor DESs exhibited the excellent properties of the DESs composed of each of their respective HBDs, achieving good extraction performance while also displaying either lower viscosity or higher thermal decomposition temperature. Quantum chemistry methods and molecular dynamics simulations were used to study the separation mechanism and the structure–activity relationship between DESs and azeotropes; the role of hydrogen bonding in separation was analyzed.