Syntheses, Structures and Properties of Metal-Organic Frameworks

Mercury is one of the most serious heavy metal pollution sources that threaten people’s health. For decades, people have developed many technologies and materials to capture mercury from flue gas of coal-fired plant. Currently, the most effective material for mercury absorption is powdered activated carbon, which shows increased efficiency when modified with halogen functional groups such as bromine. Metal-organic frameworks (MOFs) have potential applications in mercury capture due to their fantastic properties such as high porosity and high thermal stability. More important, their pore sizes and topology structures can be controlled through choosing different organic ligands in the syntheses. However, their mercury removal properties have not been studied so far. In this project, mercury absorption properties of selected known porous MOFs were studied, and the syntheses of new porous MOFs with functional groups for mercury absorption were investigated. Three known porous MOFs for mercury sorption properties were investigated. One of these MOFs, compound 3 shows a total efficiency greater than 90% in laboratory scale tests. Moreover, three new MOFs: [Cu(Br2BDC)2](HTEA)2 ， [Co2(BrBDC)(HCOO)2(DMF)2] and Zn2(BrBDC)(Trz)2•3H2O, (BrBDC = 2,5- dibromoterepthalicate, DMF =dimethylformamide, TEA = trimethylamine, Trz=1,2,4-triazole) were synthesized successfully. The first two compounds have two-dimensional structures, while the last compound contains three-dimensional channels with opening over 4.7 Å