The Feasibility of Ni-Alumina Catalysts in Oxidative Dehydrogenation of Ethane

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1177-1191 ◽  
Author(s):  
Libor Čapek ◽  
Lukáš Vaněk ◽  
Lucie Smoláková ◽  
Roman Bulánek ◽  
Jiří Adam
Keyword(s):  
Oxidative Dehydrogenation ◽  
Thermal Pretreatment ◽  
Nickel Aluminate ◽  
Highly Active ◽  
Tetrahedral Sites ◽  
Vis Spectroscopy ◽  
Ethane To Ethene ◽  
Nickel Species ◽  
The Relationship ◽  
Alumina Catalysts

The contribution deals with the development on the efficient Ni-alumina catalyst for the oxidative dehydrogenation (ODH) of ethane to ethene. The performance of Ni-alumina catalysts with varying nickel loadings and with thermal pretreatment was studied. We contribute to the understanding of the relationship between the activity of nickel species in ODH of ethane and its distribution. To analyze this effect, Ni-alumina catalysts were analyzed by UV-VIS spectroscopy, and H2-TPR profile. Ni-alumina catalysts were highly active and selective (ca. 80%) in the ODH of ethane. The catalysts contained both tetrahedral and octahedral nickel species, suggesting that nickel aluminate represented a partial spinel, where Ni(II) ions occupy both octahedral and tetrahedral sites of the oxygen lattice. It was suggested that the octahedral nickel species were more active than the tetrahedral ones.

Annealing effect on the optical and photoelectrochemical properties of lead oxide

2018 ◽  
Vol 84 (3) ◽  
pp. 30301 ◽  
Author(s):  
Wided Zerguine ◽  
Djamila Abdi ◽  
Farid Habelhames ◽  
Meriem Lakhdari ◽  
Hassina Derbal-Habak ◽  
...  
Keyword(s):  
Lead Oxide ◽  
Orthorhombic Phase ◽  
Heat Treatments ◽  
Photoelectrochemical Properties ◽  
X Ray Diffraction ◽  
Vis Spectroscopy ◽  
Size And Morphology ◽  
Two Phases ◽  
P Type ◽  
The Relationship

Effect of the annealing oxidation time of electrodeposited lead (Pb) on the phase formation of lead oxide (PbO) films is reported. The phase structure, optical properties, size and morphology of the films were investigated by scanning electron microscopy, X-ray diffraction and UV-vis spectroscopy. The relationship between structur and photoelectrochemical properties was investigated. Thin films of PbO produced via air annealing of electrodeposited lead consist of a mixture of two phases, orthorhombic (o-PbO) and tetragonal (t-PbO), that determine the material properties and effectiveness as absorber layer in a photoelectrochemical device. The proportion of tetragonal t-PbO increases for longer heat treatments. After 40 h, the sample consists mainly of tetragonal t-PbO. The p-type semiconducting behavior of lead oxide was studied by photocurrent measurements. Different heat treatments yield variations in the ratio of tetragonal to orthorhombic lead oxide that effect on device performances, where devices with a higher content of tetragonal t-PbO show higher photocurrent than with the orthorhombic phase.

A Magnetically Ordered Non-Stoichiometric Zinc Ferrite for the Oxidative Dehydrogenation Reactions.

2001 ◽  
Vol 676 ◽  
Author(s):  
J. A. Toledo ◽  
N. Nava ◽  
X. C. Sun ◽  
X. Bokhimi
Keyword(s):  
Catalytic Activity ◽  
Oxidative Dehydrogenation ◽  
Spinel Structure ◽  
Zinc Ferrite ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Octahedral Sites ◽  
Tetrahedral Sites ◽  
Dehydrogenation Reactions ◽  
Hydrothermal Reduction

ABSTRACTZnFe2O4 nanoparticles were prepared by hydrothermal reduction approach. A considerable amount of α-Fe2O3 was segregated in the as-synthesized sample, which diffused into the tetrahedral and octahedral sites of the ZnFe2O4 spinel structure with increasing the annealing temperature. The introduction of Fe3+ into the tetrahedral positions was observed by Mössbauer spectra. Magnetization measurements showed an unusual ferrimagnetic behavior of the ZnFe2O4 phase, even at room temperature, confirming the introduction of Fe3+ into the tetrahedral sites of the spinel structure. Catalytic activity measured in the oxidative dehydrogenation of 1-butene reaction increased with increasing annealing temperature, indicating that those interactions of Fe3+ in tetrahedral and octahedral positions also promotes the activity and selectivity to butadiene formation.

scholarly journals Oxidative Dehydrogenation of Propane over Vanadium-Containing Faujasite Zeolite

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1961 ◽  
Author(s):  
Małgorzata Smoliło ◽  
Katarzyna Samson ◽  
Ting Zhou ◽  
Dorota Duraczyńska ◽  
Małgorzata Ruggiero-Mikołajczyk ◽  
...  
Keyword(s):  
Oxidative Dehydrogenation ◽  
Gas Flow ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Oxidative Dehydrogenation Of Propane ◽  
Reaction Products ◽  
Promising Alternative ◽  
Vis Spectroscopy ◽  
Gas Flow Reactor ◽  
Faujasite Zeolite

Oxidative dehydrogenation (ODH) of light alkanes to olefins—in particular, using vanadium-based catalysts—is a promising alternative to the dehydrogenation process. Here, we investigate how the activity of the vanadium phase in ODH is related to its dispersion in porous matrices. An attempt was made to synthesize catalysts in which vanadium was deposited on a microporous faujasite zeolite (FAU) with the hierarchical (desilicated) FAU as supports. These yielded different catalysts with varying amounts and types of vanadium phase and the porosity of the support. The phase composition of the catalysts was confirmed by X-ray diffraction (XRD); low temperature nitrogen sorption experiments resulted in their surface area and pore volumes, and reducibility was measured with a temperature-programmed reduction with a hydrogen (H2-TPR) method. The character of vanadium was studied by UV-VIS spectroscopy. The obtained samples were subjected to catalytic tests in the oxidative dehydrogenation of propane in a fixed-bed gas flow reactor with a gas chromatograph to detect subtract and reaction products at a temperature range from 400–500 °C, with varying contact times. The sample containing 6 wt% of vanadium deposited on the desilicated FAU appeared the most active. The activity was ascribed to the presence of the dispersed vanadium ions in the tetragonal coordination environment and support mesoporosity.

Highly active and stable Co3O4 catalyst for the Low-temperature oxidative dehydrogenation of propane

2020 ◽  
Vol 112 ◽  
pp. 107725 ◽  
Author(s):  
Lei Wang ◽  
Chengcheng Ao ◽  
Yitong Zhai ◽  
Beibei Feng ◽  
Junrui Duan ◽  
...  
Keyword(s):  
Low Temperature ◽  
Oxidative Dehydrogenation ◽  
Oxidative Dehydrogenation Of Propane ◽  
Highly Active

scholarly journals Oxidative dehydrogenation of isobutane over supported V-Mo mixed oxides

2010 ◽  
Vol 75 (8) ◽  
pp. 1115-1124 ◽  
Author(s):  
Gheorghiţa Mitran ◽  
Ioan-Cezar Marcu ◽  
Adriana Urdă ◽  
Ioan Săndulescu
Keyword(s):  
Oxidative Dehydrogenation ◽  
Mixed Oxides ◽  
Catalytic Performance ◽  
Molybdenum Oxides ◽  
Impregnation Method ◽  
N2 Adsorption ◽  
Wet Impregnation ◽  
Vis Spectroscopy ◽  
Wet Impregnation Method ◽  
Oxidative Dehydrogenation Of Isobutane

Vanadium-molybdenum oxides supported on Al2O3, CeO2 and TiO2 were prepared by a ?wet? impregnation method, characterized using DRX, N2 adsorption, UV-Vis spectroscopy, electrical conductivity measurements and tested in the oxidative dehydrogenation of isobutane. The catalytic performance in the oxidative dehydrogenation of isobutane at 400-550?C depended on the nature of support and on the content of VMoO species on the support. The catalysts supported on alumina were more active and selective than those supported on ceria and titania.

Molybdenum–vanadium supported on mesoporous alumina catalysts for the oxidative dehydrogenation of ethane

2006 ◽  
Vol 117 (1-3) ◽  
pp. 228-233 ◽  
Author(s):  
B SOLSONA ◽  
A DEJOZ ◽  
T GARCIA ◽  
P CONCEPCION ◽  
J NIETO ◽  
...  
Keyword(s):  
Oxidative Dehydrogenation ◽  
Mesoporous Alumina ◽  
Oxidative Dehydrogenation Of Ethane ◽  
Alumina Catalysts

A Comparison of Grain Boundary Monolayer Segregation Measurements Made Using Fegstem and Auger Spectroscopy

1996 ◽  
Vol 439 ◽  
Author(s):  
S. B. Fisher ◽  
P. Spellward ◽  
R. Scowen ◽  
B. Lee
Keyword(s):  
Grain Boundary ◽  
Boundary Data ◽  
Auger Spectroscopy ◽  
Theoretical Description ◽  
Electron Optics ◽  
Highly Active ◽  
Active Electron ◽  
Nickel Base ◽  
Boundary Chemistry ◽  
The Relationship

AbstractThe active electron optics suite at Magnox Electric's Berkeley Centre has a VG HB501 FEGSTEM and a FE-sourced Auger Microprobe (a Fisons Microlab-F) which are routinely used for grain boundary chemistry studies in a variety of highly active austenitic and ferritic steels and nickel base alloys.In a number of investigations sufficient grain boundary data have been obtained to allow a meaningful comparison between the two instruments to be made. It has been established that for the overwhelming majority of materials and conditions there exists a reasonable correlation between the two sets of compositional (on-boundary) data.This paper presents this correlation and gives a simple theoretical description justifying the relationship between the raw data from the instruments. Examples are given of materials and conditions for which the correlation cannot be established and this leads to a discussion of the usefulness of the availability of the correlation.

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