Unit Thommes: Texture and adsorption properties of porous systems

Texture and adsorption properties of porous systems

The third sub-area of the FPS Core Facility is headed by M. Thommes (Chair of Thermal Process Engineering; TVT). The research deals with the adsorption, phase and wetting behaviour of fluids in pores and at the adsorbent interface [11-13]. This makes it possible to obtain information about the surface and pore structure of materials, but also to comprehensively analyse the adsorption properties of materials. An important aim here is to determine the structure-property-process relationships in areas such as gas and energy storage, separation technology and heterogeneous catalysis.
The range of experimental methods includes a whole series of state-of-the-art techniques for determining the adsorption and gas storage properties of adsorbents and their textural characterisation. This includes a high-resolution, manometric adsorption measuring stand, which allows both physisorption and chemisorption measurements to be carried out. The adsorption behaviour of various fluids/adsorptives can be investigated over a wide temperature range from 20 K to ~ 330 K. Adsorption at high pressures and temperatures (> 273 K) can be analysed using a high-precision magnetic suspension balance. Furthermore, a special device is available for high-resolution and precise measurement of the adsorption behaviour of vapours (e.g. water, alcohols, etc.). A new breakthrough curve measuring device coupled with mass spectroscopy allows the adsorption behaviour of gas mixtures to be investigated even for very small sample quantities, which is particularly interesting for the investigation of new types of porous materials that are often only available in very small quantities. A porosity measuring stand consisting of devices for mercury-silver porosimetry and several gas pycnometers allows the determination of meso- and macroporosity as well as bulk and framework densities. The textural characterisation of porous materials in a liquid phase is carried out using NMR relaxometry, inverse size exclusion chromatography and a new technique based on conductivity measurements.