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

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...
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.
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 ...
Raman Frequencies calculated as a function of pressure for the rotatory lattice mode in ammonia solid II near the melting point
Yurtseven, Hasan Hamit (2004-04-01)
This study gives our calculations for the Raman frequencies of the rotatory lattice mode in ammonia solid II near the melting point. The Raman frequencies of this mode are calculated as a function of the pressure using the volume data for the fixed temperatures of 230.4 K, 263.4 K, and 297.5 K by means of our Gruneisen relation. Our calculated frequencies can be examined experimentally when the Raman measurements are performed at various pressures for the constant temperatures considered.
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.