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Bridging the pressure and materials gap: in-depth characterization and reaction studies of silver-catalyzed acrolein hydrogenation

Bron, Michael and Teschner, Detre and Knop-Gericke, Axel and Steinhauer, Bernd and Scheybal, Andreas and Hävecker, Michael and Wang, Di and Födisch, Ringo and Hönicke, Dieter and Wootsch, Attila and Schlögl, Robert and Claus, Peter (2005):
Bridging the pressure and materials gap: in-depth characterization and reaction studies of silver-catalyzed acrolein hydrogenation.
In: Journal of Catalysis, Elsevier Inc., pp. 37-47, 234, [Online-Edition: http://dx.doi.org/10.1016/j.jcat.2005.05.018],
[Article]

Abstract

The gas-phase hydrogenation of acrolein over silver was studied in a broad pressure range from not, vert, similar2 mbar to 20 bar and with various silver materials (single crystals, sputtered silver, silica-supported Ag nanoparticles) in an attempt to examine the question of the “pressure and materials gap” in catalysis. High pressures and nanoparticles favour the formation of allyl alcohol (selectivities up to 42%), whereas with the opposite conditions propionaldehyde is by far the main product. A critical minimum reaction pressure was identified: below ca. 100 mbar, no allyl alcohol was formed. In situ-XAS measurements were performed at 7.5 mbar to gain insight into the interaction of acrolein with silver samples. Despite the fact that beam-induced processes have been observed, it is concluded that at low pressures, acrolein orients parallel to the surface on Ag(111) and is present at the surface in the form of hydrogenated propionaldehyde-like species. The influence of catalyst structure and pressure on the adsorption geometry of acrolein and the possible rate-determining step in acrolein hydrogenation are discussed.

Item Type: Article
Erschienen: 2005
Creators: Bron, Michael and Teschner, Detre and Knop-Gericke, Axel and Steinhauer, Bernd and Scheybal, Andreas and Hävecker, Michael and Wang, Di and Födisch, Ringo and Hönicke, Dieter and Wootsch, Attila and Schlögl, Robert and Claus, Peter
Title: Bridging the pressure and materials gap: in-depth characterization and reaction studies of silver-catalyzed acrolein hydrogenation
Language: English
Abstract:

The gas-phase hydrogenation of acrolein over silver was studied in a broad pressure range from not, vert, similar2 mbar to 20 bar and with various silver materials (single crystals, sputtered silver, silica-supported Ag nanoparticles) in an attempt to examine the question of the “pressure and materials gap” in catalysis. High pressures and nanoparticles favour the formation of allyl alcohol (selectivities up to 42%), whereas with the opposite conditions propionaldehyde is by far the main product. A critical minimum reaction pressure was identified: below ca. 100 mbar, no allyl alcohol was formed. In situ-XAS measurements were performed at 7.5 mbar to gain insight into the interaction of acrolein with silver samples. Despite the fact that beam-induced processes have been observed, it is concluded that at low pressures, acrolein orients parallel to the surface on Ag(111) and is present at the surface in the form of hydrogenated propionaldehyde-like species. The influence of catalyst structure and pressure on the adsorption geometry of acrolein and the possible rate-determining step in acrolein hydrogenation are discussed.

Journal or Publication Title: Journal of Catalysis
Volume: 234
Publisher: Elsevier Inc.
Uncontrolled Keywords: Acrolein; Silver; Selective Hydrogenation; Pressure gap; Materials gap; In situ-XAS
Divisions: 07 Department of Chemistry
07 Department of Chemistry > Fachgebiet Technische Chemie > Technische Chemie II
07 Department of Chemistry > Fachgebiet Technische Chemie
Date Deposited: 20 Mar 2009 08:48
Official URL: http://dx.doi.org/10.1016/j.jcat.2005.05.018
Identification Number: doi:10.1016/j.jcat.2005.05.018
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