Determination of intracrystalline diffusion coefficient of organic solvents in metal organic framework adsorbents by zero-length column method

A special setup was assembled to study solvent adsorption by metal organic frameworks (MOFs). A blank test was run to examine the noise level and the kinetic desorption curves for solvent molecules under different carrier gas (N2) flow rates were measured with the instrument error lying within a limited range. The desorption process could be adequately characterized by the transport of adsorbates in pores within MOFs. For the MOF samples NH2-MIL-101(Fe), HKUST-1, MIL-101(Cr), ZiF-67, and ZIF-8, the intercrystalline diffusion coefficient of ethanol, toluene, and propan-2-ol at 25, 35, and 45 degrees C were calculated and the activation energy was evaluated. The diffusion data obtained are in agreement with those reported earlier.