Synthesis and Applications of Metal-Organic Frameworks in Adsorptive Separations

Abstract

Metal-organic frameworks (MOFs) are a recently-identi ed new class of hybrid porous material, consisting of metal ions or cluster linked together by organic bridging ligands. MOFs have shown tremendous potential in adsorptive separation applications and gas storage owing to some of their extraordinary features in terms of speci c surface area, pore volume, low to moderate heat of adsorption and fairly uniform pore size distribution. This project work is focused on the synthesis and characterization of di erent MOFs and their application in adsorptive separations. MOFs are crystalline compound consisting of metal ions/cluster coordinated to often rigid organic molecules to form one, two, three dimensional structures that can be porous. The pore size and surface properties of these materials can be tuned to a great extent with relative ease by choosing appropriate metal centers and organic ligands. MOFs have got advantages over ex- isting porous materials and zeolite. They possess a wide array of potential applications including materials for gas storage, gas/vapor separation, catalysis, luminescence, and drug delivery. Firstly, In this exploratory kind of project work synthesis of varriuos MOFs using di erent metal precursor and ligand have done based on solvotheraml method except for RMOF -3. 1,4 - benzenedicarboxylic acid ligand based ve (RMOF-1,RMOF-2,RMOF-5,RMOF-6,RMOF-11), and 1,3,5 benzenetricarboxylic acid based three ( RMOF-3,RMOF-7,RMOF-10) MOFs were synthe- sised. RMOF-3 was synthesised by crystallization method. Various characterization techniques were applied to study the properties of these MOFs. X-ray powder di raction (PXRD), BET sur- face area, di erential scanning calorimetry analysis(DSC) and thermogravimetric analysis (TGA) were extensively used. Adsoptive separation studies using MOFs as a ansorbent and various liquid organic compounds as a adsorbate were performed. Among the eight MOFs were synthesised, all MOFs shows pos- itive results towards adsorptive separations for selected guest compunds. RMOF -5 and RMOF- 3 proved prominent adsorbent among all MOFs synthesized. The adsorption was found to be dependent on concentration of adsorbate by keeping adsobent consatant.