Synthesis, characterisation and gas absorption studies for metal organic framework materials

Abstract

Recently, porous metal organic framework materials (MOFs) have attracted considerable attention due to the wide range of possible applications of the materials in 1) gas storage, purification and separation; 2) as catalysts and catalyst supports; and 3) for adsorption of environmentally unfriendly species. This study has involved the synthesis, characterisation and determination of the adsorption/desorption characteristics of functionalised porous metal organic framework materials. The overall objective was to increase understanding of the role of surface functional groups and framework flexibility in determining the adsorption characteristics of gases and vapours and assess the possible applications of these materials for gas storage and separation....Adsorption of hydrogen, nitrogen, oxygen and argon were studied in order to investigate the possible applications of metal organic framework NEW-1 in gas storage and air separation. In case of the air separation, adsorption characteristics of O2, N2, and Ar on metal organic framework NEW-1, mixed-zinc/copper organic framework (M’MOF-1) and a carbon based molecular sieve (CMS-40) were compared. The crucial factors such as molecular size and shape in relation to pore structure in determining the adsorption characteristics on materials were investigated. Selected kinetic models i.e. stretched exponential model (SE), double stretched exponential model (DSE) were used to determine the kinetic adsorption parameters. Also, the isosteric enthalpies of gases adsorption at zero surface coverage were determined. The results show that very narrow pores are required in metal organic frameworks to achieve kinetic selectivity similar to CMS-40.