Synthesis, Characterization and Catalytic Activity of Ternary Oxide Catalysts Using the Microwave-Assisted Solution Combustion Method

Ni−Co−Al, Ni−Cu−Al and Co−Cu−Al ternary oxide catalysts, with a fixed 5 wt% transition metal loading, were prepared by the microwave-assisted solution combustion method and tested in CO oxidation. The bulk and surface properties of the catalysts were investigated, using XRD, N2 adsorption–desorption, SEM, XPS and TEM techniques. XRD, XPS and TEM results revealed that nickel and cobalt were present as spinels on the surface and in the bulk. Differently, copper was preferentially present in “bulk-like” CuO-segregated phases. No interaction between the couples of transition metal species was detected, and the introduction of Cu-containing precursors into the Ni−Al or Co−Al combustion systems was not effective in preventing the formation of NiAl2O4 and CoAl2O4 spinels in the Ni− or Co-containing catalysts. Copper-containing catalysts were the most active, indicating that copper oxides are the effective active species for improving the CO oxidation activity.

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Influence of the Fuel/Oxidant Ratio on the Elaboration of Binary Oxide Catalyst by a Microwave-Assisted Solution Combustion Method

Energies ◽

10.3390/en13123126 ◽

2020 ◽

Vol 13 (12) ◽

pp. 3126

Author(s):

Kawthar Frikha ◽

Simona Bennici ◽

Jamel Bouaziz ◽

Kamel Chaari ◽

Lionel Limousy

Keyword(s):

Metal Oxide ◽

Co Oxidation ◽

Combustion Method ◽

Oxide Catalysts ◽

Metal Oxide Catalysts ◽

Solution Combustion ◽

Solution Combustion Method ◽

Oxidation Activity ◽

Binary Metal ◽

Binary Metal Oxide

Three series of binary metal oxide catalysts containing Ni, Cu, or Co oxides were prepared, fully characterized and tested in CO oxidation. The catalysts, with a constant transition metal loading of 10 wt%, were prepared from metal nitrates and urea mixtures by a microwave-assisted solution combustion method. The RV/OV ratio, corresponding to the stoichiometry of the reactants, calculated from their elemental oxidizing and reducing valences, was varied. In order to modify the redox character of the synthesis medium from the quantity of urea; an excess of urea was used for attaining reducing conditions, while a deficit of urea shifted the medium to oxidizing conditions. Three RV/OV ratios (0.9, 1.0, and 1.1) were selected to elaborate the different binary metal oxide catalysts, nine oxide catalysts were synthesized. Then, the influence of the stoichiometry (RV/OV ratio) on the bulk and surface properties of the binary metal oxide catalysts was investigated. Similarly, the influence of the RV/OV ratio on the CO oxidation activity was discussed and the optimal value of RV/OV ratio was identified. The results show that the increasing of the RV/OV ratio from 0.9 to 1.1, particularly in Ni- and Co-containing catalysts, induces stronger metal-aluminum interactions, in the form of aluminates phases, and that are correlated to the dramatic reduction of the CO oxidation activity. The best physicochemical properties and highest catalytic activities were achieved with the catalysts prepared in redox systems stoichiometrically balanced (RV/OV = 1). The Cu-containing catalysts presented the best catalytic activities in CO oxidation.

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Thermoluminescence properties of MgO:Al3+,Li+ prepared by microwave-assisted solution combustion method

Physica B Condensed Matter ◽

10.1016/j.physb.2020.412008 ◽

2020 ◽

Vol 582 ◽

pp. 412008 ◽

Cited By ~ 1

Author(s):

S.J. Mofokeng ◽

L.L. Noto ◽

D.V. Mlotswa ◽

V.R. Orante-Barrón ◽

M.S. Dhlamini

Keyword(s):

Combustion Method ◽

Solution Combustion ◽

Solution Combustion Method ◽

Microwave Assisted

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A facile synthesis of CuCe and CuCeFe mixed-oxide catalysts by solution combustion method for catalytic methane combustion

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/778/1/012061 ◽

2020 ◽

Vol 778 ◽

pp. 012061

Author(s):

P Kruemek ◽

S Mattathankul ◽

N Triamnak ◽

N Chotigkrai

Keyword(s):

Mixed Oxide ◽

Methane Combustion ◽

Combustion Method ◽

Oxide Catalysts ◽

Facile Synthesis ◽

Solution Combustion ◽

Solution Combustion Method ◽

Mixed Oxide Catalysts

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Microwave-Assisted Synthesis of Mixed Metal-Oxide Nanoparticles

Journal of Nanoparticles ◽

10.1155/2013/737831 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 6

Author(s):

Akrati Verma ◽

Reena Dwivedi ◽

R. Prasad ◽

K. S. Bartwal

Keyword(s):

Oxidation State ◽

Combustion Method ◽

Mixed Metal Oxide ◽

Average Particle ◽

Particle Sizes ◽

Solution Combustion ◽

Solution Combustion Method ◽

Xps Spectra ◽

Mixed Metal ◽

Microwave Assisted

Nanoparticles of mixed metal oxides, ZrO2, ZrTiO4, and ZrV2O7 were prepared by microwave-assisted citrate sol-gel and solution combustion method. The prepared nanoparticles were characterized for their structural details using XRD and TEM techniques. The broadening of Raman bands is ascribed to local compositional fluctuations or local positional disordering produced due to random distribution of Zr4+ and Ti4+between equivalent sites. The XPS spectra confirm the incorporation of Ti in ZrO2 and suggest Zr as well as Ti in +4 oxidation state. Gelation and fast combustion seem to be the reason for smaller particle sizes. ZrV2O7 nanocrystalline material was synthesized by microwave- assisted solution combustion method. Low angle powder XRD measurements confirm the mesoporous nature of the prepared material. The effect of calcination temperature on the phase transformation of the materials has been investigated. Among tetragonal, monoclinic, and cubic phases, the monoclinic phase is predominant at higher calcinations temperature. The XPS confirms the incorporation of V2O5 in ZrO2 and suggests that Zr and V are in the same oxidation state (+4). The average particle sizes for ZrO2, ZrTiO4, and ZrV2O7 were found to be in the ranges of 5–10 nm, 2–5 nm, and 10–50 nm, respectively.

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Catalytic oxidation of CO over CuO/CeO2 nanocomposites synthesized via solution combustion method: effect of fuels

REVIEWS ON ADVANCED MATERIALS SCIENCE ◽

10.1515/rams-2020-0002 ◽

2020 ◽

Vol 59 (1) ◽

pp. 131-143 ◽

Cited By ~ 1

Author(s):

Thanh Son Cam ◽

Tatyana Alekseevna Vishnievskaia ◽

Vadim Igorevich Popkov

Keyword(s):

Low Temperature ◽

Co Oxidation ◽

Combustion Method ◽

X Ray Diffraction ◽

Solution Combustion ◽

Solution Combustion Method ◽

X Ray ◽

Low Temperature Co Oxidation ◽

Temperature Programmed ◽

Adsorption Desorption

AbstractA series of CuO/CeO2 catalysts were successfully synthesized via solution combustion method (SCS) using different fuels and tested for CO oxidation. The catalysts were characterized by energy-dispersive X-ray analysis (EDXA), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), N2 adsorption-desorption isotherms and H2 temperature-programmed reduction (H2-TPR). It was found that the used fuels strongly affected the characterization and the low-temperature reduction behavior of CuO/CeO2 catalysts. The CuO/CeO2-urea catalyst exhibited higher catalytic activity toward CO oxidation (t50=120∘C, t100=159∘C) than the 5 other synthesized catalysts. In addition, the CuO/CeO2-urea catalyst displayed high stability for CO oxidation during five cycles and water resistance. The enhanced catalytic CO oxidation of the synthesized samples can be attributed by a combination of factors, such as smaller crystallite size, higher specific surface area, larger amount of amorphous copper(II) oxide, more mesoporous and uniform spherical-like structure. These findings are worth considering in order to continue the study of the CuO/CeO2 catalyst with low-temperature CO oxidation.

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