Effect of Synthesis Temperature on Water Adsorption in UiO-66 Derivatives: Experiment, DFT+D Modeling, and Monte Carlo Simulations

Abstract

In this work, density functional theory (DFT) and Monte Carlo calculations were combined with standard volumetric adsorption as well as quasi-equilibrated temperature-programmed desorption and adsorption measurements to study water adsorption in UiO-66 derivatives containing -NH2, -NO2, and -Br substituents. Based on DFT modeling, both the position and geometry of the substituents were determined and one model was selected for each structure. By using Monte Carlo simulations and the force field developed in our previous work for the adsorption of water in metal-organic frameworks, we reproduced experimental adsorption isotherms and isobars. The results allow us to explain the water adsorption process in UiO-66 derivatives. Detailed physicochemical characterization by means of elemental analysis, powder X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis enabled us to determine the influence of the synthesis temperature on the structure and properties of the materials.