SYNTHESIS, CHARACTERIZATIONS, AND ADSORPTION ISOTHERMS OF CO2 ON CHROMIUM TEREPHTHALATE (MIL-101) METAL-ORGANIC FRAMEWORKS (MOF)

The concentration of CO2 in the atmosphere caused by fossil fuels, power plants, and transportation is the most significant environmental issue in the world today. Intensive efforts have been made to minimize CO2 levels to reduce global warming. Metal-organic frameworks (MOFs), crystalline porous materials, exhibit great potential to adsorb carbon dioxide. In the present study, research was conducted on the synthesis, characterization, and adsorption isotherms of MIL-101. MIL-101, one type of mesoporous MOF, can adsorb enormous amounts of CO2. The synthesis was carried out using a fluorine-free hydrothermal reaction method. The porous properties, structure, morphology, thermal stability, and chemical functionalities of MIL-101 Cr were measured by N-2 adsorption/desorption isotherms, X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. The volumetric uptakes of CO2 were experimentally measured at temperatures of 298-308 K and pressure of up to 600 kPa. The experimental result was correlated with the Toth isotherm model, showing the heterogeneity of the adsorbent. The heat of adsorption of MIL-101 was determined from the measured isotherm data, indicating the strength between the adsorbent and adsorbate molecule.