Vapor phase solvents loaded in zeolite as the sustainable medium for the preparation of Cu-BTC and ZIF-8

Solvent-evaporated conversion (SEC) and steam-assisted conversion (SAC) have been developed to prepare the typical metal-organic frameworks (MOFs) Cu-BTC (HKUST-1) and ZIF-8 using a unique solvent recovery strategy using zeolite. As a green circulation medium, zeolite Na-4A loading and removal of solvent (H 2 O and EtOH) can transport solvent in the vapor phase and avoid solvent condensation, which was the defect in previous SAC syntheses of MOFs, and achieves efficient solvent recovery as well as being an economical and green synthetic process. Moreover, SEC and SAC processes exhibited different mechanisms during the multi-stage reaction and solid diffusion reaction, respectively and both can synthesize the desired products in 12   h. These two methods for MOFs preparation were characterized in detail using XRD, SEM and N 2 adsorption during the different growing stages. According to polar molecules (H 2 O and EtOH) steam-assisted in those synthesis, polar destruction molecules (H 2 O, NH 3 ) adsorption and stability of Cu-BTC and ZIF-8 was investigated.