Estimation of the desorption energy of dichloromethane and water in MIL-53 by DSC and ab-initio calculations

Desorption energies of dichloromethane (CH2Cl2) and water (H2O) in a metal-organic framework, MIL-53(Al), were investigated by the combination of experimental (differential scanning calorimeter, DSC) and computational (ab-initio calculations) methods. The differences of desorption energy and natural log of the frequency factor of CH2Cl2 and H2O in MIL-53(Al) were analyzed by a thermo active process using DSC measurements. The interaction energy of guest molecules with MIL-53(Al), which correspond to the desorption in the thermal active process, was explored using ab-initio calculation. As a result of the difference in the interaction energies of H2O and CH2Cl2 in MIL-53(Al), the site near the mu(2)-OH groups has two potential wells. Both experimentally and computationally, MIL-53 presents the preferential adsorption of CH2Cl2 than H2O.