Diffusion and Gas Transport in Reticular Materials

Mass transfer in reticular materials is often discussed broadly in terms of adsorption “rates,” although the reported quantity depends on the relevant length scale, the physical driving force, and the extent to which the experiment isolates the intended transport process. This mini‐review introduces diffusion in reticular materials, with emphasis on metal‐organic frameworks. Different definitions of adsorption kinetics, including self‐diffusion, transport diffusion, and barrier‐controlled transport, are introduced to clarify what common gas adsorption experiments measure and how these quantities should be interpreted. Widely used experimental methods are reviewed, with emphasis on challenges associated with heat effects, external resistances, and engineered material form. Selected examples show how framework chemistry can tune diffusion, how coadsorption and defects can produce unexpected behavior, and how measured diffusion data can connect to larger‐scale system performance.