The Journey from Porous Materials to Metal-organic Frameworks and their Catalytic Applications: A Review.

Metal-Organic Frameworks (MOFs), a class of inorganic-organic hybrid materials, have been at the center of material science for the past three decades. They are synthesized by metal ions and organic linker precursors and have become very potential materials for different applications ranging from sensing, separation, catalytic behaviour to biomedical applications and drug delivery, owing to their structural flexibility, porosity and functionality. They are also very promising in heterogeneous catalysis for various industrial applications. These catalysts can be easily synthesized with extremely high surface areas, tunable pore sizes, and incorporation of catalytic centers via post-synthetic modification (PSM) or exchange of their components as compared to traditional heterogeneous catalysts, which is the preliminary requirement of a better catalyst. Here, in this review, we have presented the history of MOFs, different synthesis procedures, and MOFcatalysed reactions; for instance, coupling reactions, condensation reactions, Friedel-Crafts reaction, oxidation, etc. Special attention has been given to MOFs containing different catalytic centers, including open metal sites, incorporation of catalytic centers through PSM, and bifunctional acidbase sites. The important role of catalytic centers present in MOFs and reaction mechanisms have also been outlined with examples.