Adsorptive Separation of Benzene, Cyclohexene, and Cyclohexane by Amorphous Nonporous Solids of Amide Naphthotubes

Benzene hydrogenation is one of important industrial processes. The reaction is incomplete, resulting in a mixture of benzene, cyclohexane and/or cyclohexene which have to be separated before the following reactions. The currently-used extractive and azeotropic distillations are operationally complex and energy-intensive. Adsorptive separation provides an alternative energy-efficient method. However, the separation of the ternary mixture has not been reported with adsorptive separation. In the present research, we report two macrocyclic hosts with hydrogen bonding sites in their cavities, which are able to separate the ternary mixture of benzene, cyclohexene and cyclohexane. N-H⋅⋅⋅π interactions were found to play a key role in the selective separation. In addition, fast adsorption, high loading ratios and easy recycling are achieved with the present system, promising for practical applications.