Characterization and Comparison of the Performance of IRMOF-1, IRMOF-8, and IRMOF-10 for CO2Adsorption in the Subcritical and Supercritical Regimes

Abstract

Using Expanded Wang–Landau simulations, we have determined with great accuracy the grand-canonical partition function of CO2 adsorbed in IRMOF-1, IRMOF-8, and IRMOF-10. Then, following a solution thermodynamics approach to adsorption, we use the partition function so obtained to calculate the immersion and desorption free energy, enthalpy, and entropy, which provide a complete thermodynamic characterization of the three systems. Excess and immersion functions are found to be monotonic functions of pressure in the subcritical regime and to present an extremum in the supercritical regime. However, for both regimes, our results show the predominant contribution of the immersion enthalpy to the excess enthalpy of adsorption and the lesser contribution of the other two immersion functions (Gibbs free energy and entropy) to the corresponding excess functions. The results also indicate that the desorption free energy, corresponding to the minimum isothermal work required to regenerate the adsorbent, is directly ...