Thermodynamics of metal-organic frameworks: from fundamentals to advanced applications

The fundamental thermodynamics of metal-organic frameworks (MOFs) is a key aspect that defines the suitability of MOFs for a wide range of applications, including as sorbents for gas storage and water harvesting, solid-state electrolytes, radionuclide storage materials, and heterogeneous catalysts. However, reliable experimental evaluation of thermodynamic parameters related to, for example, framework stability, guest adsorption or binding, and phase transitions can be challenging due to MOF insolubility, limited diffusion of analytes through framework pores, and potential structural defects. The presented review aims to discuss practical methods and accessible experimental techniques, such as calorimetry, thermal measurements, absorbance and emission spectroscopies, and electrochemical experiments, for determining various thermodynamic aspects that are useful for predicting and tailoring MOF performance. By highlighting the advantages and potential outcomes of each class of considered techniques, this review serves as a guide for selecting and combining experimental methods to evaluate the detailed thermodynamics and kinetics of MOF-based processes, ranging from framework formation, post-synthetic modification, diffusion and binding of guest molecules, phase changes, and energy storage. In addition, this review highlights how theoretical modeling could potentially complement experimental work to provide a more comprehensive overview of the MOF thermodynamic landscape. Overall, each of the discussed case studies emphasizes how fundamental thermodynamics can shed light on the design of functional materials to address emergent global challenges in the technological, energy, and biomedical sectors and beyond.