DFT investigation of high temperature water gas shift reaction on chromium-iron mixed oxide catalyst

2014-11-20
Yalcin, Ozgen
Önal, Işık
As part of high temperature water gas shift reaction mechanism, CO adsorption and H2O adsorption on Fe3O4 (111) and chromium atom substituted Fe3O4 (111) slab surfaces are investigated by means of periodic DFT approach using VASP. Fe3O4 bulk structure has been computed including the Hubbard (U) parameter. One oxygen site (Ooct1) is studied as a probable site among the six Fe3O4 (111) terminations. Cr atom substitution on this surface is also examined. Cr atoms prefer being on the surface rather than in the bulk structure and Cr atoms substitute on the octahedral iron atom layer (Ooct2Cr). Adsorption energies of CO on Ooct1 and Ooct2Cr are found as -96 kcal/mol and -47 kcal/mol. Water adsorption on Ooct1 surface is molecular with -54.88 kcal/mol adsorption energy. On the other hand, water adsorption on Ooct2Cr surface is dissociative with nearly same adsorption energy, -55.12 kcal/mol, indicating the catalytic effect of chromium atom. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

Suggestions

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...
Investigation of ruthenium-copper bimetallic catalysts for direct epoxidation of propylene: A DFT study
Kizilkaya, Ali Can; Senkan, Selim; Önal, Işık (2010-09-01)
Propylene epoxidation reactions are carried out on Ru-Cu(1 1 1) and Cu(1 1 1) surfaces with periodic density functional theory (DFT) calculations. Ru-Cu(1 1 1) surface is modeled as Cu(1 1 1) monolayer totally covering the Ru(0 0 0 1) surface underneath, in accordance with the literature. It is shown that the Ru-Cu(1 1 1) surface is ineffective for propylene oxide formation since it has a lower energy barrier (0.48 eV) for the stripping of the allylic hydrogen of propylene and a higher energy barrier (0.92 ...
DFT Study on the Hydrogenation of CO2 to Methanol on Ho-Doped Cu(211) Surface
Tezsevin, Ilker; Senkan, Selim; Önal, Işık; Duzenli, Derya (2020-10-01)
The catalytic conversion of carbon dioxide (CO2) into methanol, a valuable chemical product, has been investigated theoretically on a novel holmium (Ho)-doped Cu(211) surface by density functional theory (DFT) calculations. The possible key intermediates formed during the hydrogenation of CO2 and as well as their further hydrogenated species during the production of methanol are examined thermodynamically and kinetically by computational means. It is found that the adhesion of a Ho atom on the Cu(211) surfa...
DSC STUDIES ON MELT CRYSTALLIZED, DRAWN AND FUMING NITRIC-ACID OXIDIZED POLYETHYLENE
Akar, Ahmet; Zaim, Ömer; Tinçer, Teoman; Aydoğan, A. Cevdet (Wiley, 1989-4)
Melting, recrystallisation and remelting of undrawn and drawn linear polyethylene with different molecular weight were studied by differential scanning calorimetry before and after oxidation with nitric acid.
A density functional theory study of partial oxidation of propylene on Cu2O(001) and CuO(001) surfaces
Duzenli, Derya; Atmaca, Deniz Onay; Gezer, Miray Gulbiter; Önal, Işık (2015-11-15)
This work theoretically investigates propylene epoxidation reaction on Cu2O(001) and CuO(001) surfaces using periodical DFT method to determine the active copper species within the reaction mechanism. The transition states and energy profiles are calculated for the formation of surface intermediates such as oxametallopropylene (OMP) over Cu2O(0 0 1) and oxygen bridging (OB) over CuO(0 0 1) and allylic H-stripping reaction (AHS) over both surfaces as well as for formation of products. Propylene oxide (PO) an...
Citation Formats
O. Yalcin and I. Önal, “DFT investigation of high temperature water gas shift reaction on chromium-iron mixed oxide catalyst,” INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, pp. 19563–19569, 2014, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/31380.