Stofftransport in mikro‐ und mesoporösen Materialien

Mass Transfer in Micro‐ and Mesoporous Materials Mass transfer in micro‐ and mesoporous materials is of crucial relevance for their practical application to separation and catalysis, since the mobility of adsorbed molecules ultimately limits the rate of the overall processes. Diffusion, i.e. the irregular thermal motion of the molecules, is the dominating process. Diffusion measurements are therefore indispensable for the evaluation of the quality parameters of porous materials. Being able to directly follow the diffusion path of the molecules, microscopic techniques hold a key position among the various methods of diffusion measurement. Besides their fundamentals, the contribution describes the application of these techniques to the investigation of structure‐mobility relations in zeolites and in mesoporous materials of type MCM‐41. As features of particular technological relevance, the phenomena of correlated diffusion anisotropy, of single‐file diffusion, and of molecular traffic control are discussed in detail.