Volume 41, Issue 9 pp. 1871-1880
Research Article

Spatially Resolved Characterization of the Gas Propagator in Monolithic Structured Catalysts Using NMR Diffusiometry

Mojtaba Mirdrikvand

Corresponding Author

Mojtaba Mirdrikvand

University of Bremen, Department of Chemistry, In vivo MR Group, Leobener Strasse 7, 28359 Bremen, Germany

Correspondence: Mojtaba Mirdrikvand ([email protected]), University of Bremen, Department of Chemistry, In vivo MR Group, Leobener Strasse 7, 28359 Bremen, Germany.Search for more papers by this author
Jan Ilsemann

Jan Ilsemann

University of Bremen, Institute of Applied and Physical Chemistry, Department of Chemistry, Leobener Strasse 6, 28359 Bremen, Germany

Search for more papers by this author
Jorg Thöming

Jorg Thöming

University of Bremen, Center of Environmental Research and Sustainable Technology (UFT), Leobener Strasse 6, 28359 Bremen, Germany

Search for more papers by this author
Wolfgang Dreher

Wolfgang Dreher

University of Bremen, Department of Chemistry, In vivo MR Group, Leobener Strasse 7, 28359 Bremen, Germany

Search for more papers by this author
First published: 18 July 2018
Citations: 4

Abstract

Gas diffusivity measurements in opaque porous media were performed using nuclear magnetic resonance. An optimized pulsed-field gradient stimulated echo method with free volume selection was used to investigate the propagator of thermally polarized methane gas within commercial monolithic catalyst supports. Since signal losses due to T2 relaxation were minimized by using a short echo time, diffusion processes could be characterized by the measured propagator functions and effective diffusion coefficients were determined for a broad range of observation times and in different spatial directions. The study of this noninvasive characterization of gas diffusion found a clear effect of the monolith type and its pore size and coating on the effective gas diffusion coefficient and the apparent tortuosity for a given observation time.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.