Abstract
Kinetics and modeling of 1-phenyl-1,2-propanedione hydrogenation over cinchonidine-modified Pt/Al2O3 catalyst is reported. Hydrogenation experiments carried out in a pressurized autoclave (288 K, 1.2-6.5 bar hydrogen) revealed interesting kinetic effects which inspired the model development. The enantioselectivity towards the (R)-configuration, as well as the reaction rate and regioselectivity, depended on the modifier concentration having a maximum. The enantio- and regioselective effects were explained by the kinetic model, which assumes different number of sites for adsorption of the carbonyl groups of the 1-phenyl-1,2-propanedione as well as for the cinchonidine adsorbed in flat and tilted modes. The number of adsorption sites needed for the different species were obtained from molecular considerations and the hydrogenation rate constants were determined along with the adsorption parameters by non-linear regression analysis. A comparison of model predictions with experimental data revealed that the model accounts for the kinetic regularities.
| Original language | English |
|---|---|
| Pages (from-to) | 7-16 |
| Number of pages | 10 |
| Journal | Journal of Catalysis |
| Volume | 213 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2003 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work is part of the activities at the Åbo Akademi Process Chemistry Group within the Finnish Centre of Excellence Programme (2000–2005) of the Academy of Finland. Financial support from the Finnish Graduate School in Chemical Engineering (GSCE) is gratefully acknowledged. The unknown referee is acknowledged for numerous suggestions, which helped to improve the manuscript.
Keywords
- Diones
- Enantioselectivity
- Hydrogenation
- Kinetic model
- Multicentered adsorption
- Regioselectivity