2022 Volume 65 Issue 2 Pages 37-49
Metal-organic frameworks (MOFs) have unique properties such as micropores, crystalline structure, and high specific surface area. These properties are advantages for adsorption/separation, catalyst support/catalyst, and other processes. This review discusses the preparation, characterization and uses of MOFs. Various MOFs were prepared by hydro- and solvo-thermal methods and were characterized with XRD, N2 adsorption/desorption, TG-DTA, FT-IR, SEM and TEM. Most prepared MOFs were phase-pure, crystalline and microporous. To demonstrate the usefulness of specific MOFs, oligomerization of ethylene, chemo- and regio-selective hydrogenation of cinnamaldehyde and phenyl-1,3-butadiene, cross-coupling, and separation of aromatics were investigated. To effectively utilize the microporous structure of MOF, selection of raw materials was important for reactants to enter the micropores. In addition, fine control of the sizes of micropores to restrict the approach of substrate to the active site was essential, for example, by use of protecting groups. Pore size was critical for the separation of aromatics. Separation of p-xylene from a xylene mixture of similar kinetic molecular sizes by molecular sieving was attained for the first time.
