title: Microimaging of transient concentration profiles of reactant and product molecules during catalytic conversion in nanoporous materials.
abstract: Microimaging by IR microscopy is applied to the recording of the evolution of the concentration profiles of reactant and product molecules during catalytic reaction, notably during the hydrogenation of benzene to cyclohexane by nickel dispersed within a nanoporous glass. Being defined as the ratio between the reaction rate in the presence of and without diffusion limitation, the effectiveness factors of catalytic reactions were previously determined by deliberately varying the extent of transport limitation by changing a suitably chosen system parameter, such as the particle size and by comparison of the respective reaction rates. With the novel options of microimaging, effectiveness factors become accessible in a single measurement by simply monitoring the distribution of the reactant molecules over the catalyst particles.
authors.affiliation: Department of Interface Physics, University of Leipzig, Linnéstrasse 5, 04103 Leipzig (Germany).
authors.forename: Tobias
authors.initials: T
authors.lastname: Titze
authors.forename: Christian
authors.initials: C
authors.lastname: Chmelik
authors.forename: Jens
authors.initials: J
authors.lastname: Kullmann
authors.forename: Lutz
authors.initials: L
authors.lastname: Prager
authors.forename: Erich
authors.initials: E
authors.lastname: Miersemann
authors.forename: Roger
authors.initials: R
authors.lastname: Gläser
authors.forename: Dirk
authors.initials: D
authors.lastname: Enke
authors.forename: Jens
authors.initials: J
authors.lastname: Weitkamp
authors.forename: Jörg
authors.initials: J
authors.lastname: Kärger
keywords: glasses; heterogeneous catalysis; reaction kinetics; reaction mechanisms; supported catalysts