Regensburg 2010 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 15: Poster: Nuclear Magnetic Resonance - Frontiers and Applications

CPP 15.9: Poster

Montag, 22. März 2010, 16:30–18:00, Poster C

Transport and high-pressure phase equilibria in mesopores — •Philipp Zeigermann, Muslim Dvoyashkin, Jörg Kärger, and Rustem Valiullin — Department of Interface Physics, University of Leipzig, Germany

Heterogeneous catalysis in high-pressure environments is a standard process in state-of-the-art industrial chemical synthesis. Micro- and mesoporous materials are widely used as hosts for the catalysts, while educts and products are delivered and removed under high pressure conditions. The supercritical state is here of particular interest because of its superior dynamical properties (low viscosity, no surface tension, high diffusivity).

Despite of its advantages in various applications, high-pressure phase equilibria in mesoporous host materials, and especially their interrelation with transport properties, are still poorly understood. Recently, it was shown that pulsed field gradient nuclear magnetic resonance spectroscopy (PFG NMR) is a particularly suitable tool to probe diffusion properties of sub- and near-critical fluids in mesopores.

A special NMR sample vessel has been constructed which permits to maintain pressures up to 200 bars. In this way it is possible to measure pressure-dependent self-diffusivities of organic compounds solved in supercritical solvents, e.g., in carbon dioxide in the bulk state as well as in the mesopores. Some preliminary results on molecular diffusivities at different conditions will be presented.