TU Darmstadt / ULB / TUbiblio

Mechanism of Selective Hydrogenation of α,β-Unsaturated Aldehydes on Silver Catalysts: A Density Functional Study

Kim, Kok Hwa ; Mohammad, Amjad B. ; Yudanov, Ilya V. ; Neyman, Konstantin M. ; Bron, Michael ; Claus, Peter ; Rösch, Notker :
Mechanism of Selective Hydrogenation of α,β-Unsaturated Aldehydes on Silver Catalysts: A Density Functional Study.
[Online-Edition: http://dx.doi.org/10.1021/jp902078c]
In: The Journal of Physical Chemistry C, 113 (30) pp. 13231-13240.
[Artikel], (2009)

Offizielle URL: http://dx.doi.org/10.1021/jp902078c

Kurzbeschreibung (Abstract)

Supported silver catalysts exhibit a remarkably high selectivity in the industrially important hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols. We carried out density functional calculations to clarify factors that affect the catalytic function of silver in hydrogenating unsaturated aldehydes. We examined the activity and the selectivity of model silver catalysts for acrolein, the simplest, yet most difficult unsaturated aldehyde to be selectively hydrogenated. We focused on describing bulky catalyst particles, represented by sites on extended silver surfaces, on the regular clean Ag(110) surface and the surface Osub/Ag(111) with subsurface oxygen centers. On Ag(110) our results imply propanal, the undesired saturated aldehyde, to be the main product. In contrast, the calculations suggest a very high selectivity of Osub/Ag(111) for the corresponding unsaturated alcohol, allyl alcohol, although the activity of this system is lower than that of clean silver. At variance with Pt(111), where the selectivity to allyl alcohol is strongly reduced by the hindered desorption of the latter, allyl alcohol and propanal products are predicted to desorb easily from both Ag(110) and Osub/Ag(111) at common reaction temperatures. We also analyzed inherent limitations for an accurate description of the chemical regioselectivity by contemporary computational methods.

Typ des Eintrags: Artikel
Erschienen: 2009
Autor(en): Kim, Kok Hwa ; Mohammad, Amjad B. ; Yudanov, Ilya V. ; Neyman, Konstantin M. ; Bron, Michael ; Claus, Peter ; Rösch, Notker
Titel: Mechanism of Selective Hydrogenation of α,β-Unsaturated Aldehydes on Silver Catalysts: A Density Functional Study
Sprache: Englisch
Kurzbeschreibung (Abstract):

Supported silver catalysts exhibit a remarkably high selectivity in the industrially important hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols. We carried out density functional calculations to clarify factors that affect the catalytic function of silver in hydrogenating unsaturated aldehydes. We examined the activity and the selectivity of model silver catalysts for acrolein, the simplest, yet most difficult unsaturated aldehyde to be selectively hydrogenated. We focused on describing bulky catalyst particles, represented by sites on extended silver surfaces, on the regular clean Ag(110) surface and the surface Osub/Ag(111) with subsurface oxygen centers. On Ag(110) our results imply propanal, the undesired saturated aldehyde, to be the main product. In contrast, the calculations suggest a very high selectivity of Osub/Ag(111) for the corresponding unsaturated alcohol, allyl alcohol, although the activity of this system is lower than that of clean silver. At variance with Pt(111), where the selectivity to allyl alcohol is strongly reduced by the hindered desorption of the latter, allyl alcohol and propanal products are predicted to desorb easily from both Ag(110) and Osub/Ag(111) at common reaction temperatures. We also analyzed inherent limitations for an accurate description of the chemical regioselectivity by contemporary computational methods.

Titel der Zeitschrift, Zeitung oder Schriftenreihe: The Journal of Physical Chemistry C
Band: 113
(Heft-)Nummer: 30
Fachbereich(e)/-gebiet(e): Fachbereich Chemie
Fachbereich Chemie > Technische Chemie > Technische Chemie II
Fachbereich Chemie > Technische Chemie
Hinterlegungsdatum: 20 Jul 2009 10:06
Offizielle URL: http://dx.doi.org/10.1021/jp902078c
Zusätzliche Informationen:

Publication Date (Web): 7. Juli 2009

ID-Nummer: 10.1021/jp902078c
Export:

Optionen (nur für Redakteure)

Eintrag anzeigen Eintrag anzeigen