A methodology towards 3D visualization and quantification of liquids in porous materials by means of cryogenic Electron Tomography (Cryo-ET) is being developed and used to study impregnated catalyst supports.
Filling the pores of a hierarchical ceramic material with liquids is a central process utilized in applications such as adsorption, separation or catalyst preparation. In each of these applications the interaction of the respective liquid is controlled by the pore structure and surface chemistry of the ceramic host material. To gain understanding of how the pores and their surface structure affect the interaction with a liquid phase and species dissolved in it, it is desirable to have a 3D representation of its native (i.e., filled) state. This can be accomplished by means of cryo-ET. However, imaging liquids within a porous system at cryogenic temperatures is not a routine measurement, because the liquid phase is prone to electron beam damage. Furthermore, the preparation of such samples for cryo-ET is challenging because the specimen needs to be sufficiently small (< 500 nm), impregnated, and vitrified. This project aims at developing a methodology and workflow to properly image the native state of liquid containing porous materials.