Kinetic modeling of α-hydrogen abstractions from unsaturated and saturated oxygenate compounds by carbon-centered radicals
- Author
- Paschalis Paraskevas (UGent) , Maarten Sabbe (UGent) , Marie-Françoise Reyniers (UGent) , Nikos Papayannakos and Guy Marin (UGent)
- Organization
- Abstract
- Hydrogen abstractions are important elementary reactions in a variety of reacting media at high temperatures in which oxygenates and hydrocarbon radicals are present. Accurate kinetic data are obtained from CBS-QB3 ab initio (AI) calculations by using conventional transition-state theory within the high-pressure limit, including corrections for hindered rotation and tunneling. From the obtained results, a group-additive (GA) model is developed that allows the Arrhenius parameters and rate coefficients for abstraction of the a-hydrogen from a wide range of oxygenate compounds to be predicted at temperatures ranging from 300 to 1500 K. From a training set of 60 hydrogen abstractions from oxygenates by carbon-centered radicals, 15 GA values (Delta GAV degrees s) are obtained for both the forward and reverse reactions. Among them, four Delta GAV degrees s refer to primary contributions, and the remaining 11 Delta GAV degrees s refer to secondary ones. The accuracy of the model is further improved by introducing seven corrections for cross-resonance stabilization of the transition state from an additional set of 43 reactions. The determined Delta AV degrees s are validated upon a test set of AI data for 17 reactions. The mean absolute deviation of the pre-exponential factors (log A) and activation energies (Ea) for the forward reaction at 300 K are 0.238 log(m(3) mol(-1) s(-1)) and 1.5 kJ mol(-1), respectively, whereas the mean factor of deviation <rho > between the GA-predicted and the AI-calculated rate coefficients is 1.6. In comparison with a compilation of 33 experimental rate coefficients, the <rho > between the GA-predicted values and these experimental values is only 2.2. Hence, the constructed GA model can be reliably used in the prediction of the kinetics of a-hydrogen-abstraction reactions between a broad range of oxygenates and oxygenate radicals.
- Keywords
- GROUP ADDITIVE VALUES, PHASE STANDARD ENTHALPY, HYDROCARBON RADICALS, BETA-SCISSION REACTIONS, TRANSITION-STATE-THEORY, group additivity, hydrogen abstraction, kinetic modeling, oxygen, ab initio calculations, REACTION-RATE PREDICTION, DIMETHYL ETHER, AB-INITIO, METHYL RADICALS, ACTIVATION-ENERGIES
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Citation
Please use this url to cite or link to this publication: http://hdl.handle.net/1854/LU-5674724
- MLA
- Paraskevas, Paschalis, et al. “Kinetic Modeling of α-Hydrogen Abstractions from Unsaturated and Saturated Oxygenate Compounds by Carbon-Centered Radicals.” CHEMPHYSCHEM, vol. 15, no. 9, 2014, pp. 1849–66, doi:10.1002/cphc.201400039.
- APA
- Paraskevas, P., Sabbe, M., Reyniers, M.-F., Papayannakos, N., & Marin, G. (2014). Kinetic modeling of α-hydrogen abstractions from unsaturated and saturated oxygenate compounds by carbon-centered radicals. CHEMPHYSCHEM, 15(9), 1849–1866. https://doi.org/10.1002/cphc.201400039
- Chicago author-date
- Paraskevas, Paschalis, Maarten Sabbe, Marie-Françoise Reyniers, Nikos Papayannakos, and Guy Marin. 2014. “Kinetic Modeling of α-Hydrogen Abstractions from Unsaturated and Saturated Oxygenate Compounds by Carbon-Centered Radicals.” CHEMPHYSCHEM 15 (9): 1849–66. https://doi.org/10.1002/cphc.201400039.
- Chicago author-date (all authors)
- Paraskevas, Paschalis, Maarten Sabbe, Marie-Françoise Reyniers, Nikos Papayannakos, and Guy Marin. 2014. “Kinetic Modeling of α-Hydrogen Abstractions from Unsaturated and Saturated Oxygenate Compounds by Carbon-Centered Radicals.” CHEMPHYSCHEM 15 (9): 1849–1866. doi:10.1002/cphc.201400039.
- Vancouver
- 1.Paraskevas P, Sabbe M, Reyniers M-F, Papayannakos N, Marin G. Kinetic modeling of α-hydrogen abstractions from unsaturated and saturated oxygenate compounds by carbon-centered radicals. CHEMPHYSCHEM. 2014;15(9):1849–66.
- IEEE
- [1]P. Paraskevas, M. Sabbe, M.-F. Reyniers, N. Papayannakos, and G. Marin, “Kinetic modeling of α-hydrogen abstractions from unsaturated and saturated oxygenate compounds by carbon-centered radicals,” CHEMPHYSCHEM, vol. 15, no. 9, pp. 1849–1866, 2014.
@article{5674724, abstract = {{Hydrogen abstractions are important elementary reactions in a variety of reacting media at high temperatures in which oxygenates and hydrocarbon radicals are present. Accurate kinetic data are obtained from CBS-QB3 ab initio (AI) calculations by using conventional transition-state theory within the high-pressure limit, including corrections for hindered rotation and tunneling. From the obtained results, a group-additive (GA) model is developed that allows the Arrhenius parameters and rate coefficients for abstraction of the a-hydrogen from a wide range of oxygenate compounds to be predicted at temperatures ranging from 300 to 1500 K. From a training set of 60 hydrogen abstractions from oxygenates by carbon-centered radicals, 15 GA values (Delta GAV degrees s) are obtained for both the forward and reverse reactions. Among them, four Delta GAV degrees s refer to primary contributions, and the remaining 11 Delta GAV degrees s refer to secondary ones. The accuracy of the model is further improved by introducing seven corrections for cross-resonance stabilization of the transition state from an additional set of 43 reactions. The determined Delta AV degrees s are validated upon a test set of AI data for 17 reactions. The mean absolute deviation of the pre-exponential factors (log A) and activation energies (Ea) for the forward reaction at 300 K are 0.238 log(m(3) mol(-1) s(-1)) and 1.5 kJ mol(-1), respectively, whereas the mean factor of deviation <rho > between the GA-predicted and the AI-calculated rate coefficients is 1.6. In comparison with a compilation of 33 experimental rate coefficients, the <rho > between the GA-predicted values and these experimental values is only 2.2. Hence, the constructed GA model can be reliably used in the prediction of the kinetics of a-hydrogen-abstraction reactions between a broad range of oxygenates and oxygenate radicals.}}, author = {{Paraskevas, Paschalis and Sabbe, Maarten and Reyniers, Marie-Françoise and Papayannakos, Nikos and Marin, Guy}}, issn = {{1439-4235}}, journal = {{CHEMPHYSCHEM}}, keywords = {{GROUP ADDITIVE VALUES,PHASE STANDARD ENTHALPY,HYDROCARBON RADICALS,BETA-SCISSION REACTIONS,TRANSITION-STATE-THEORY,group additivity,hydrogen abstraction,kinetic modeling,oxygen,ab initio calculations,REACTION-RATE PREDICTION,DIMETHYL ETHER,AB-INITIO,METHYL RADICALS,ACTIVATION-ENERGIES}}, language = {{eng}}, number = {{9}}, pages = {{1849--1866}}, title = {{Kinetic modeling of α-hydrogen abstractions from unsaturated and saturated oxygenate compounds by carbon-centered radicals}}, url = {{http://doi.org/10.1002/cphc.201400039}}, volume = {{15}}, year = {{2014}}, }
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