Synthesis, immobilization and acid‑catalyzed application of binary and ternary deep eutectic solvent: Synthesis of diphenylamine by condensation of aniline

Abstract

Binary and ternary acidic deep eutectic solvents (ADES) were synthesized by using choline chloride as hydrogen bond acceptor, trifluoromethanesulfonic acid and glycerol as hydrogen bond donors, respectively. They were immobilized on β zeolite. The structure and surface morphology were characterized by FTIR, 1H NMR, XRD and SEM, which proved the successful preparation and immobilization of ADES. The catalytic performance of the materials was investigated by the reaction of aniline condensation to prepare diphenylamine. Both ADES and immobilized ADES showed extremely high catalytic activity. Among them, immobilized ADES as a new heterogeneous catalytic material, breaks through the limitation of difficult separation of homogeneous catalysts, and has high economy, high activity and environmental protection. The hydrogen bonding interaction and catalytic mechanism between the components were further discussed in combination with the reaction mechanism.