Synthesis, characterization and investigation of gas adsorption properties of bipyridine lewis base containing zirconium metal-organic frameworks

The most important factor limiting the practical use of metal-organic frameworks which is the favorite materials of recent years is their chemical and thermal stability like other chemicals. The UiO-67 (UiO = University of Oslo) type metal-organic frameworks prepared with zirconium and Lewis basic sites containing 2,2'-bipyridine-5,5'-dicarboxylic acid, which is useful for many purposes, has low stability in protic solvents such as water and ethanol. In this thesis, in order to increase the hydrolytic stability of Lewis basic sites containing frameworks and to utilize these free Lewis basic sites, methyl substituted dicarboxylic acid around pyridine nitrogen, 6,6-dimethyl-[2,2'-bipyridine]-5,5'-dicarboxylic acid, was syntesized and an UiO-67 type new metal-organic framework (MOF-553) with zirconium was prepared. The prepared framework was then transformed into a framework containing gold and platinum chloride using the pyridine nitrogen atoms of the Lewis basic sites and characterized by various methods such as elemental analysis, thermal analysis, IR spectroscopy, powder X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. Brunauer-Emmett-Teller surface areas of the frameworks were calculated using low temperature nitrogen adsorption isotherms. Adsorption capacities of H2, CO2, CH4 gases of prepared frameworks were investigated.