Cobalt-Based Metal-Organic Frameworks for Adsorption of CO2 and C2 Hydrocarbons: Effect of Auxiliary Ligands with Different Functional Groups

Recently, metal-organic frameworks (MOFs) have been investigated as potential materials for CO₂ capture and light hydrocarbon storage/separation due to their high porosity, large surface area, and tunable skeleton structures. In this work, the six cobalt-based MOFs 1-6 were successfully synthesized under solvothermal conditions by a mixed-ligand strategy. 1 and 2 have the same framework structure with a topology of {4²·5}₂{4⁴·5¹⁰·6⁷·7⁶·8}, while the structures of the 3-6 frameworks are the same with a topology of {4²·5}₂{4⁴·5¹⁰·6⁹·7⁴·8}. The adsorption properties of these MOFs for CO₂ and C₂ hydrocarbons were then investigated, and the effect of the functional groups was discussed. The results revealed that the introduction of amino and bromo groups could effectively strengthen the adsorption performance.

Metal-Organic Frameworks: Synthetic Methods and Potential Applications

Metal-organic frameworks represent a porous class of materials that are build up from metal ions or oligonuclear metallic complexes and organic ligands. They can be considered as sub-class of coordination polymers and can be extended into one-dimension, two-dimensions, and three-dimensions. Depending on the size of the pores, MOFs are divided into nanoporous, mesoporous, and macroporous items. The latter two are usually amorphous. MOFs display high porosity, a large specific surface area, and high thermal stability due to the presence of coordination bonds. The pores can incorporate neutral molecules, such as solvent molecules, anions, and cations, depending on the overall charge of the MOF, gas molecules, and biomolecules. The structural diversity of the framework and the multifunctionality of the pores render this class of materials as candidates for a plethora of environmental and biomedical applications and also as catalysts, sensors, piezo/ferroelectric, thermoelectric, and magnetic materials. In the present review, the synthetic methods reported in the literature for preparing MOFs and their derived materials, and their potential applications in environment, energy, and biomedicine are discussed.