Gas diffusion mechanisms and diffusion coefficients in microkinetic system of solid materials
characterize the different performance of chemical and transport processes. These factors should be
evaluated with respect to the range of diffusion coefficients based on the number of experimental
methods. Here, impedance spectroscopy which is a powerful tool for understanding transport
phenomena of gases in nanostructured porous solids is used. In this work, we developed a new
approach to compare and evaluate diffusion coefficients of isopropanol in the zeolite H-ZSM5.
Furthermore, FTIR spectroscopy was used to study the adsorption of isopropanol in H-ZSM5 at
different temperatures to support the interpretation of diffusion regimes. The combination of EIS with
FTIR enables to illustrate preferred interaction sites and their influence on transport processes. The
activation energy for transport of molecules in the channels is also calculated. Results are compared to
literature data and suggest improved applications of EIS to characterize transport processes