TU Darmstadt / ULB / TUbiblio

Silver as acrolein hydrogenation catalyst: intricate effects of catalyst nature and reactant partial pressures

Bron, Michael and Teschner, Detre and Knop-Gericke, Axel and Jentoft, Friederike C. and Kröhnert, Jutta and Hohmeyer, Jens and Volckmar, Claudia and Steinhauer, Bernd and Schlögl, Robert and Claus, Peter (2007):
Silver as acrolein hydrogenation catalyst: intricate effects of catalyst nature and reactant partial pressures.
In: Physical Chemistry Chemical Physics, pp. 3559-3569, 9, (27), [Online-Edition: http://dx.doi.org/10.1039/b701011g],
[Article]

Abstract

The hydrogenation of acrolein over pure and supported silver has been investigated with a focus on the influence of catalyst structure and reaction pressure (mbar to 20 bar range) on activity and selectivity. An onset of formation of allyl alcohol beyond 100 mbar reaction pressure (at 250 °C) is ascribed to a change in adsorption geometry upon increasing coverage. Smaller silver particles (in the nanometer range), the proximity of a reducible oxide component as well as high pressure lead to enhanced allyl alcohol formation; the selectivity to the other main product propionaldehyde is reduced. The silver dispersion changed depending on the reaction pressure. Moreover, the presence of oxygen, most likely as subsurface oxygen, and the presence of defects are of paramount importance for the catalytic behaviour. The considerable changes of the silver catalysts under reaction conditions and the pressure dependence call for in situ measurements to establish true structure–activity/selectivity relationships for this system.

Item Type: Article
Erschienen: 2007
Creators: Bron, Michael and Teschner, Detre and Knop-Gericke, Axel and Jentoft, Friederike C. and Kröhnert, Jutta and Hohmeyer, Jens and Volckmar, Claudia and Steinhauer, Bernd and Schlögl, Robert and Claus, Peter
Title: Silver as acrolein hydrogenation catalyst: intricate effects of catalyst nature and reactant partial pressures
Language: English
Abstract:

The hydrogenation of acrolein over pure and supported silver has been investigated with a focus on the influence of catalyst structure and reaction pressure (mbar to 20 bar range) on activity and selectivity. An onset of formation of allyl alcohol beyond 100 mbar reaction pressure (at 250 °C) is ascribed to a change in adsorption geometry upon increasing coverage. Smaller silver particles (in the nanometer range), the proximity of a reducible oxide component as well as high pressure lead to enhanced allyl alcohol formation; the selectivity to the other main product propionaldehyde is reduced. The silver dispersion changed depending on the reaction pressure. Moreover, the presence of oxygen, most likely as subsurface oxygen, and the presence of defects are of paramount importance for the catalytic behaviour. The considerable changes of the silver catalysts under reaction conditions and the pressure dependence call for in situ measurements to establish true structure–activity/selectivity relationships for this system.

Journal or Publication Title: Physical Chemistry Chemical Physics
Volume: 9
Number: 27
Divisions: 07 Department of Chemistry
07 Department of Chemistry > Fachgebiet Technische Chemie
07 Department of Chemistry > Fachgebiet Technische Chemie > Technische Chemie II
Date Deposited: 20 Mar 2009 09:01
Official URL: http://dx.doi.org/10.1039/b701011g
Additional Information:

First published on the web 30. Mai 2007

Identification Number: doi:10.1039/b701011g
Export:

Optionen (nur für Redakteure)

View Item View Item