Application of response surface methodology to optimize high active Cu-Zn-Al mixed metal oxide fabricated via microwave-assisted solution combustion method

2020 ◽  
Vol 31 (4) ◽  
pp. 1470-1479 ◽  
Author(s):  
Mojgan Hashemzehi ◽  
Vahid Pirouzfar ◽  
Hamed Nayebzadeh ◽  
Afshar Alihosseini
Keyword(s):  
Response Surface Methodology ◽  
Metal Oxide ◽  
Response Surface ◽  
Combustion Method ◽  
Mixed Metal Oxide ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Mixed Metal ◽  
Microwave Assisted

scholarly journals Microwave-Assisted Synthesis of Mixed Metal-Oxide Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
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.

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

2020 ◽  
Vol 582 ◽  
pp. 412008 ◽  
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

Synthesize of magnetite Mg-Fe mixed metal oxide nanocatalyst by urea-nitrate combustion method with optimal fuel ratio for reduction of emissions in diesel engines

2020 ◽  
Vol 838 ◽  
pp. 155627
Author(s):  
Nasrin Sabet Sarvestani ◽  
Mohammad Hossein Abbaspour-Fard ◽  
Mohammad Tabasizadeh ◽  
Hamed Nayebzadeh ◽  
Thuy Chu Van ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Diesel Engines ◽  
Combustion Method ◽  
Mixed Metal Oxide ◽  
Mixed Metal ◽  
Fuel Ratio ◽  
Urea Nitrate ◽  
Reduction Of Emissions

scholarly journals Microwave-Assisted Aldol Condensation of Furfural and Acetone over Mg–Al Hydrotalcite-Based Catalysts

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 833
Author(s):  
Alberto Tampieri ◽  
Matea Lilic ◽  
Magda Constantí ◽  
Francesc Medina
Keyword(s):  
Metal Oxide ◽  
Fossil Fuel ◽  
Aldol Condensation ◽  
Polymeric Materials ◽  
Mixed Metal Oxide ◽  
Mixed Metal ◽  
Microwave Assisted ◽  
Condensation Products ◽  
Microwave Reactor ◽  
Co Precipitation

The depletion of fossil fuel resources has prompted the scientific community to find renewable alternatives for the production of energy and chemicals. The products of the aldol condensation between bio-based furfural and acetone have been individuated as promising intermediates for the preparation of biofuels and polymeric materials. We developed a protocol for the microwave-assisted condensation of these two compounds over hydrotalcite-based materials. Mg:Al 2:1 hydrotalcite was prepared by co-precipitation; the obtained solid was calcined to afford the corresponding mixed metal oxide, which was then rehydrated to obtain a meixnerite-type material. The prepared solids were characterized by PXRD, ICP-AES, TGA-DSC and N2 physisorption, and tested as catalysts in the aldol condensation of acetone and furfural in a microwave reactor. The performance of the catalysts was assessed and compared; the meixnerite catalyst proved to be the most active, followed by the mixed metal oxide and the as-synthesized hydrotalcite, which has often been reported to be inactive. In all cases, the reaction is quite fast and selective, which makes our protocol useful for rapidly converting furfural and acetone into their condensation products.

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

Energies ◽  
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.

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

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4607
Author(s):  
Kawthar Frikha ◽  
Lionel Limousy ◽  
Jamel Bouaziz ◽  
Kamel Chaari ◽  
Simona Bennici
Keyword(s):  
Transition Metal ◽  
Co Oxidation ◽  
Combustion Method ◽  
Oxide Catalysts ◽  
Metal Species ◽  
Ternary Oxide ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Oxidation Activity ◽  
Microwave Assisted

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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