Direct gas-phase epoxidation of propylene to propylene oxide through radical reactions: A theoretical study

2010-03-05
Kizilkaya, Ali Can
Fellah, Mehmet Ferdi
Önal, Işık
The gas-phase radical chain reactions which utilize O-2 as the oxidant to produce propylene oxide (PO) are investigated through theoretical calculations. The transition states and energy profiles were obtained for each path. The rate constants were also calculated. The energetics for the competing pathways indicate that PO can be formed selectively due to its relatively low activation barrier (9.3 kcal/mol) which is in a good agreement with the experimental value (11 kcal/mol) of gas-phase propylene epoxidation. The formation of the acrolein and combustion products have relatively high activation barriers and are not favored. These results also support the recent experimental findings.
CHEMICAL PHYSICS LETTERS

Suggestions

Direct epoxidation of propylene to propylene oxide on various catalytic systems: A combinatorial micro-reactor study
Kalyoncu, Sule; Duzenli, Derya; Önal, Işık; Seubsai, Anusorn; Noon, Daniel; Senkan, Selim (2015-02-10)
A combinatorial approach is used to investigate several bimetallic catalytic systems and the promoter effect on these catalysts to develop highly active and selective catalysts for direct epoxidation of propylene to propylene oxide (PO) using molecular oxygen. 2%Cu/5%Ru/c-SiO2 catalyst yielded the highest performance with high propylene conversion and PO selectivity among the bimetallic catalytic systems including silver, ruthenium, manganese and copper metals. On the other hand, the most effective catalyst...
Direct Methane Oxidation to Methanol by N2O on Fe- and Co-ZSM-5 Clusters with and without Water: A Density Functional Theory Study
Fellah, Mehmet Ferdi; Önal, Işık (2010-02-25)
Density functional theory (DFT) calculations were carried Out ill a Study of oxidation of methane to methanol by N2O on the Fe- and Co-ZSM-5 clusters. The catalytic cycle steps have been Studied oil model Clusters ((SiH3)(4)AlO4M) (where M = Fe, Co). Calculations indicate very low methanol selectivity Without water and increasing rate of methanol formation with water. These results are in qualitative agreement with the experimental literature. The methanol formation step is also found to be the rate-limitin...
Partial oxidation of methane on the SiO2 surface - A quantum chemical study
Ozturk, S; Onal, I; Senkan, S (2000-02-01)
Reaction pathways for methane partial oxidation (MPO) on silica were theoretically investigated using the semiempirical MOPAC-PM3 molecular orbital method. The surface of SiO2 was modeled by a helical Si6O18H12 molecular cluster that also exhibits a strained siloxane bridge defect. First, a bond energy analysis was performed on the silica cluster with isolated 3- and 4-coordinated Si surface atoms. Calculated bond dissociation energies for Si-H, SiO-H, and SI-OH were comparable to H-CH3, H-OH, and O-O. In t...
Oxidative coupling of methane over NbO (p-type) and Nb2O5 (n-type) semiconductor materials
Erarslanoglu, Y; Onal, I; Doğu, Timur; Senkan, S (Springer Science and Business Media LLC, 1996-01-01)
Oxidative coupling of methane to higher hydrocarbons was investigated using two types of semiconductor catalysts, NbO (p-type) and Nb2O5 (n-type) at 1 atm pressure. The ratio of methane partial pressure to oxygen partial pressure was changed from 2 to 112 and the temperature was kept at 1023 K in the experiments conducted in a cofeed mode. The results indicated a strong correlation between C-2+ selectivity performance and the electronic properties of the catalyst in terms of p- vs. n-type conductivity. The ...
Synthesis of CuO nanostructures on zeolite-Y and investigation of their CO2 adsorption properties
Boruban, Cansu; Nalbant Esentürk, Emren (2017-10-01)
Copper(II) oxide (CuO) nanoparticles (NPs) in two different morphologies, spiky and spherical, were synthesized on zeolite-Y by a modified impregnation method, and their CO2 adsorbing capabilities were investigated under standard conditions (1 atm and 298 K). The properties and CO2 adsorption performances of the hybrid systems were characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy, atomic absorption s...
Citation Formats
A. C. Kizilkaya, M. F. Fellah, and I. Önal, “Direct gas-phase epoxidation of propylene to propylene oxide through radical reactions: A theoretical study,” CHEMICAL PHYSICS LETTERS, pp. 183–189, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32077.