Thermal conductivity of metal–organic frameworks (MOFs)

Metal–organic frameworks (MOFs) have emerged as a substantial class of porous crystalline materials, encompassing millions of newly discovered structures that exhibit diverse physical and chemical properties applicable across various sectors, including catalysis, life sciences, and energy storage and conversion. Among these properties, thermal conductivity (TC) is a critical parameter that significantly influences the performance and stability of MOFs. A particularly noteworthy characteristic of MOFs is their intrinsic porosity, which is highly tunable and directly impacts their TC. Factors such as grain size, pore size, grain boundaries, modulator incorporation, and framework thickness are instrumental in determining scattering mechanisms, including lattice defect scattering, grain boundary scattering, and phonon–phonon scattering, as well as the overall heat transfer properties. Despite its significance and the existence of several studies, including large-scale investigations involving thousands of MOF structures, the TC of MOFs has, until recently, largely been neglected and lacked systematic evaluation. This study conducts a critical evaluation of how the porosity of MOFs, characterized by various distinct morphological and structural parameters, influences TC values. It combines both experimental and computational insights to define essential design principles for thermally conductive materials MOFs. We also explore applications of MOFs with varying thermal conductivities, from ultra-low to high, and future prospects in this field. By addressing this knowledge gap, we aim to establish a foundational basis for future research focused on optimizing MOFs for high-performance thermal and energy applications, thus facilitating the realization of their full potential in energy-efficient technologies.