Amino-functionalized Zr-MOF nanoparticles for adsorption of CO ₂ and CH ₄

Amino-functionalized Zr-MOF (amino-Zr-MOF) was synthesized using 2-aminoterephthalic acid as an organic linker. The physicochemical properties of the material were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and N₂ adsorption to understand its crystalline structure, morphology, thermal stability, and porous structure. CO₂ adsorption isotherms on amino-Zr-MOF were obtained at 1 atm and at different temperatures. In addition, CO₂ and CH₄ adsorption at high pressure (up to 10 atm) was also measured. CO₂ adsorption capacity on amino-Zr-MOF was 9 mmol/g at 988 kPa, 0°C, while CH₄ adsorption capacity was 3.7 mmol/g at 900 kPa, 0°C. The heat of CO₂ adsorption on amino-Zr-MOF was estimated to be 29.4 kJ/mol. Continuous column tests of CO₂ adsorption were performed at different concentrations of CO₂ in nitrogen at 20 mL/min and 0.7 g adsorbent and total adsorbed amounts of CO₂ within the column during the breakthrough time were calculated to be 4.55, 5.26 and 4.37 mmol/g at 10%, 15% and 20%CO₂, respectively. © 2013 Taylor & Francis Group, LLC.