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

Date

2010-03-05

Author

Kizilkaya, Ali Can
Fellah, Mehmet Ferdi
Önal, Işık

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

177
views

0
downloads

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.

Subject Keywords

Molecular-oxygen, Oxidation, Ethylene, Catalysts, Adsorption, Mechanism, Silica

URI

https://hdl.handle.net/11511/32077

Journal

CHEMICAL PHYSICS LETTERS

DOI

https://doi.org/10.1016/j.cplett.2010.01.036

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

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...
Low level NO gas sensing properties of Cu doped ZnO thin films prepared by SILAR method Corlu, T.; Karaduman, I.; Galioglu, S.; Akata Kurç, Burcu; YILDIRIM, MEMET ALİ; ATEŞ, AYTÜNÇ; ACAR, SELİM (2018-02-01) We report the successful synthesis and characterization of Zn1-xCuxO (x = 0.05, 0.10, 0.15, 0.20) thin films prepared by a simple and facile Successive Ionic Layer Adsorption and Reaction (SILAR) method. The nitrogen monoxide (NO) gas sensing properties of the Zn1-xCuxO sensors were studied systematically. The sensors were proved to have acceptable responses towards 20 ppb NO gas. Zn0.90Cu0.10O exhibited improved sensing performance at operating temperature of 55 degrees C compared to other samples. To impr...
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...
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 ...

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.