Epoxidation of Ethylene by Silver Oxide (Ag2O) Cluster: A Density Functional Theory Study

Date

2011-06-01

Author

Fellah, Mehmet Ferdi
van Santen, Rutger A.
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

295
views

0
downloads

Density functional theory (DFT) calculations were employed to study epoxidation of ethylene on a [Ag14O9] cluster model representing silver oxide (001) surface. Theoretical results obtained in this study showed that formation paths of acetaldehyde and vinyl alcohol have higher activation barriers than that of ethylene oxide formation path on silver oxide (35 and 35 vs. 20 kcal/mol). Formation of the ethylene oxometallocycle intermediate is found to have a low probability on Ag2O(001) surface. The essential reason for this may be lower basicity of surface oxygen atom on silver oxide surface and the absence of a surface vacancy position to activate ethylene. Adsorbed EO is formed on Ag2O surface cluster without an activation barrier. The activation barriers of the rate-limiting steps for the production of EO mechanisms (via ethyleneoxy and non-activated paths, 20 vs. 14 kcal/mol) are in relatively good agreement with the experimental activation energy values (14, 17 and 22 kcal/mol) reported for EO formation on silver catalyst.

Subject Keywords

Basicity, Silver oxide, Non-activated path, Epoxidation, Ethylene, DFT

URI

https://hdl.handle.net/11511/31030

Journal

CATALYSIS LETTERS

DOI

https://doi.org/10.1007/s10562-011-0614-2

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Epoxidation of Propylene on a [Ag14O9] Cluster Representing Ag2O (001) Surface: A Density Functional Theory Study Fellah, Mehmet Ferdi; Önal, Işık (2012-01-01) Density functional theory calculations were employed to study partial oxidation of propylene on a [Ag14O9] cluster representing Ag2O (001) surface for which positive effect for ethylene oxide formation has been reported in our earlier work at the same level of theory (Fellah et al., Catal Lett 141: 762, 2011). Propylene oxide (PO), propanal, acetone and G-allyl radical formation reaction mechanisms were investigated. P-allyl formation path and two propylene adsorption paths resulting in PO formation are com...
Anisotropic Elastic and Lattice Dynamical Properties of Cr2AB MAX Phases Compounds Gencer, Ayşenur; Yılmaz, İnanç; Bayhan, Ülkü; Sürücü, Gökhan (2019-03-01) The structural, mechanical and lattice dynamical properties of the MAX Phase borides compounds Cr2AB (A= Al, P, Si) have been investigated using the first principles calculations with the generalized gradient approximation (GGA) based on Density Functional Theory (DFT). The obtained negative formation energies of Cr2AB indicate that these compounds are stable and could be synthesized. Some basic physical parameters such as lattice constants, elastic constants, bulk modulus, Shear modulus, Young’s modulus, a...
Dielectric and Thermal Effects on the Optical Properties of Natural Dyes: A Case Study on Solvated Cyanin Malcıoğlu, Osman Barış; Gebauer, Ralph; Varsano, Daniele; Baroni, Stefano (2011-10-05) The optical properties of the flavylium state of the cyanin dye are simulated numerically by combining Car-Parrinello molecular dynamics and linear-response time-dependent density functional theory calculations. The spectrum of the dye calculated in the gas phase is characterized by two peaks in the yellow and in the blue (green and violet), using a GGA-PBE (hybrid-B3LYP) DFT functional, which would bring about a greenish (bright orange) color incompatible with the dark purple hue observed in nature. Descri...
Adsorption of water and ammonia on TiO2-anatase cluster models

Önal, Işık; Senkan, Selim (2006-06-15)

Density functional theory (DFT) calculations performed at B3LYP/6-31G** level are employed to study water and ammonia adsorption and dissociation on (101) and (001) TiO2 anatase surfaces both represented by totally fixed and partially relaxed Ti2O9H10 cluster models. PM3 semiempirical calculations were also conducted both on Ti2O9H10 and Ti9O33H30 clusters in order to assess the effect of cluster size. Following dissociation, the adsorption of H2O and NH3 by H-bonding on previously H2O and NH3 dissociated s...
Covalent and noncovalent functionalization of pristine and defective graphene by cyclohexane and dehydrogenated derivatives Sayin, Ceren Sibel; Toffoli, Daniele; Toffoli, Hande (2015-10-01) The interaction of cyclohexane (C6H12), cyclohexyl (C6H11*) and cyclohexene (C6H10) with both pristine and defective graphene (single vacancy and a carbon adatom), is systematically investigated within the density functional theory framework. C6H12 physisorbs on both pristine and defective graphene while C6H10 chemisorbs on graphene in the presence of an adatom. The C6H11* radical binds covalently with the graphene substrate in all adsorption geometries considered.

Citation Formats

M. F. Fellah, R. A. van Santen, and I. Önal, “Epoxidation of Ethylene by Silver Oxide (Ag2O) Cluster: A Density Functional Theory Study,” CATALYSIS LETTERS, pp. 762–771, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31030.