Energetics of acrolein hydrogenation on Pt(1 1 1) and Ag(1 1 1) surfaces: a BOC-MP model study

• Published in: Journal of molecular catalysis. A, Chemical Vol. 208; no. 1; pp. 167 - 174
• Main Authors: Khanra, B.C, Jugnet, Y, Bertolini, J.C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 02.02.2004; Elsevier; Elsevier [1995, Vol. 95, n° 1-janvier 2017, vol. 426, part B]
• Subjects: Acrolein; BOC-MP model; Catalysis; Catalytic reactions; Chemical Sciences; Chemistry; DFT; Exact sciences and technology; General and physical chemistry; Propanal; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; α,β-unsaturated aldehydes; BOC-MP model; Acrolein; DFT; α,β-unsaturated aldehydes; Propanal; Catalytic reaction; Catalyst selectivity; Theoretical study; Transition metal; Crystal face; Aldehyde; Hydrogenation; Morse model; Silver; Heterogeneous catalysis; Density functional; Platinum; Ethylenic compound
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/S1381-1169(03)00507-7

Activation barriers for hydrogenation of acrolein to allyl alcohol and propanal on Pt(1 1 1) and Ag(1 1 1) surfaces are estimated by bond-order conservation-Morse potential (BOC-MP) model. A comparison of the barriers explains the lower selectivity for allyl alcohol compared to that for propanal. Bond-order conservation-Morse potential (BOC-MP) model has been used to study the energetics of acrolein hydrogenation on Pt(1 1 1) and Ag(1 1 1) surfaces. For hydrogenation at low coverage of acrolein ( θ=1/9), the model predicts an overall low activity for acrolein conversion and a lower selectivity for the formation of allyl alcohol. At higher acrolein coverage ( θ=1/4), however, the total activity increases and the selectivity for the allyl alcohol is improved compared to its magnitude at low coverage. The results are in qualitative agreement with the experimental results on hydrogenation of similar α,β-unsaturated aldehyde on Pt surfaces indicating steric hindrance for the CC bond hydrogenation at higher coverages. As for hydrogenation on Ag(1 1 1) surface, the energetics predict relatively higher selectivity for allyl alcohol compared to the selectivity on Pt(1 1 1) surface. The predictions are critically discussed with reference to the available experimental results.