ZIF-78 membrane derived from amorphous precursors with permselectivity for cyclohexanone/cyclohexanol mixture

Abstract

Cyclohexanone and cyclohexanol are products of selective oxidation of cyclohexane. They are important industrial intermediates and difficult to be separated due to their close boiling points. In this work, well-intergrown ZIF-78 membrane was successfully synthesized on the porous silica substrate by secondary growth method and applied for separation of cyclohexanone/cyclohexanol mixture for the first time. Meanwhile, a facile method for seeding procedure was developed by utilizing the amorphous ZIF-78 precursors to provide better-distributed nucleation sites. Both XRD and SEM results confirmed the good quality of the membrane. The pervaporation separation of cyclohexanone/cyclohexanol mixture were carried out at room temperature with permselectivity of 1:2 and total flux around 8.7×10−2 kgm−2 h−1.