Adsorption and Diffusion of Carbon Dioxide on Metal−Organic Framework (MOF-5)

Adsorption equilibrium and diffusion of CO2 on microporous metal−organic frameworks (MOF-5, or IRMOF-1) crystals were experimentally studied by the gravimetric method in the pressure range up to 1 atm. The MOF-5 crystal cubes of about 40−60 μm in sizes were synthesized by the solvothermal method. Freundlich adsorption isotherm equation can fit well CO2 adsorption isotherms on MOF-5, with isosteric heat of adsorption of about 34 kJ/mol. Diffusion coefficient of CO2 in the MOF-5 is in the range of 8.1−11.5 × 10−9 cm2/s in 295−331K with activation energy of 7.61 kJ/mol. MOF-5 offers attractive adsorption properties as an adsorbent for separation of CO2 from flue gas.