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

2020 ◽  
Vol 59 (1) ◽  
pp. 131-143 ◽  
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.

scholarly journals Improvement of the Photocatalytic Activity of ZnO/Burkeite Heterostructure Prepared by Combustion Method

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 817 ◽  
Author(s):  
A. Luna-Flores ◽  
M.A. Morales ◽  
R. Agustín-Serrano ◽  
R. Portillo ◽  
J.A. Luna-López ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
X Ray ◽  
Sem Image ◽  
Particle Aggregates ◽  
One Step ◽  
Ph Dependent

In this work, a novel route is discussed to produce in one step ZnO/Burkeite powders by the modified solution combustion method. The ZnO particles enhance the photocatalytic activity in the degradation of Rhodamine B, in which Burkeite mineral acts as a support due to the pH-dependent morphology of the particle aggregates of the as-synthesized powders. The X-ray diffraction (XRD) characterization shows the presence of a heterostructure: ZnO/Burkeite. The Scanning Electron Microscopy (SEM) image shows a morphological dependence with the pH of the solution used for the synthesis. The results show that the system with the highest degradation (92.4%) corresponds to the case in which ZnO/Burkeite heterostructure was synthesized with a pH 11.

EFFECT OF STRONTIUM DOPING ON NANOSTRUCTURE AND CHROMATICITY OF Y2O3:Eu COMPOUNDS

2011 ◽  
Vol 25 (22) ◽  
pp. 2949-2956 ◽  
Author(s):  
ALI MOHAMMADI ◽  
YADOLAH GANJKHANLOU ◽  
MAHMOOD KAZEMZAD ◽  
ABDOLMAJID BAYANDORI MOGHADDAM ◽  
FEREIDOUN ALIKHANI HESSARI ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Photo Luminescence ◽  
Combustion Method ◽  
Urea Solution ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
X Ray ◽  
Transmission Electron

In this work, various nano-sized samples of Y 2 O 3, Y 2 O 3 :Eu and Y 2 O 3 :Eu , Sr were prepared by urea solution combustion method. Then the resultant nanopowders were investigated by means of X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR) and photo-luminescence emission spectra. Furthermore, the CIE color coordinate of samples were calculated from photoluminescence emission spectra. Results showed that by doping of strontium, the photoluminescence intensity and chromaticity of Y 2 O 3: Eu phosphor was enhanced while crystallite size was decreased.

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

scholarly journals Green Synthesis of Ni-Cu-Zn Based Nanosized Metal Oxides for Photocatalytic and Sensor Applications

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1467
Author(s):  
Mir Waqas Alam ◽  
Muhammad Aamir ◽  
Mohd Farhan ◽  
Maryam Albuhulayqah ◽  
Mohamad M. Ahmad ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Transition Metal Oxides ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Visible Absorption ◽  
X Ray ◽  
Sensor Applications ◽  
Synthesized Materials

The preparation, characterization, and application of Nickel oxide (NiO)–Copper oxide (CuO)–Zinc oxide (ZnO) transition nanometal oxides have significantly enhanced their tunable properties for superior multifunctional performances compared with well-known metal oxides. NiO–CuO–ZnO nano transition metal oxides were synthesized by a simple eco-friendly solution combustion method. X-ray diffraction studies revealed distinct phases such as monoclinic, cubic, and hexagonal wurtzite for CuO, NiO, and ZnO, respectively, with NiO having the highest composition. The particle sizes were found to be in the range between 25 and 60 nm, as determined by powder X-ray diffraction. The energy bandgap values were found to be 1.63, 3.4, and 4.2 eV for CuO, ZnO, and NiO, respectively. All metal oxides exhibited a moderate degradation efficiency for AR88 dye. The results of ultraviolet–visible absorption spectra helped identify the bandgap of metal oxides and a suitable wavelength for photocatalytic irradiation. Finally, we concluded that the electrochemical studies revealed that the synthesized materials are well suitable for sensor applications.

X-ray powder diffraction of RE6UO12 (RE=Eu, Gd, and Dy)

2001 ◽  
Vol 16 (4) ◽  
pp. 220-223 ◽  
Author(s):  
Hrudananda Jena ◽  
R. Asuvathraman ◽  
M. V. Krishnaiah ◽  
K. V. Govindan Kutty
Keyword(s):  
Combustion Method ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Solution Combustion ◽  
Rare Earth Ion ◽  
Solution Combustion Method ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns

Powder X-ray diffraction data are reported for RE6UO12 (RE=Eu, Gd, and Dy). The powders were prepared by a solution combustion method using urea as fuel. All compositions exhibit a rhombohedral structure with hexagonal unit cell parameters of a=1.012 67 (9) nm, c=0.9601 (1) nm for Eu6UO12; a=1.008 78 (6) nm, c=0.954 24 (7) nm for Gd6UO12; and a=0.998 06 (7) nm, c=0.944 03 (8) nm for Dy6UO12. The diffraction patterns of all the compounds are indexed on the R3¯ space group with Z=3. The a and c values decrease with increasing atomic number of the rare earth ion.

Comparative Studies of the CoMo/MgO, CoMo/Al2O3 and CoMo/MgO-MgAl2O4 Catalysts Prepared by a Urea-Matrix Combustion Method

2010 ◽  
Vol 132 ◽  
pp. 45-54 ◽  
Author(s):  
Li Bao Wu ◽  
Dong Mei Jiao ◽  
Li Fang Chen ◽  
Jin An Wang ◽  
Fa Hai Cao
Keyword(s):  
Supported Catalysts ◽  
Fixed Bed ◽  
Combustion Method ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Isothermal Adsorption ◽  
X Ray ◽  
Species Formation ◽  
Temperature Programmed ◽  
Adsorption Desorption

Three CoMo supported catalysts with different supports, Al2O3, MgO and MgO-MgAl2O4, were prepared by a urea matrix combustion method. The physicochemical properties of the catalysts were characterized by N2 isothermal adsorption–desorption, powder X-ray diffraction (XRD) and temperature programmed reduction (TPR) techniques. The activity of these catalysts was evaluated in a fixed-bed high-pressure reactor using hydrodesulfurization of dibenzothiophene as a model reaction. The urea matrix combustion preparation method greatly favored the formation of highly dispersed Co- and Mo-oxo species on the support, which had significant influence on the hydrodesulfurization (HDS) activity. XRD analysis showed that MgO was more sensitive to the deposition of Co-O or Mo-O species than Al2O3 and MgAl2O4; the former might be potentially used as an indicator of the Co- and Mo-oxo species formation. Among these catalysts, CoMo/MgO-MgAl2O4 exhibited a high HDS activity.

Preparation and Characteristics of Nanocrystalline Yttria by Microwave-Induced Solution Combustion Method

2016 ◽  
Vol 697 ◽  
pp. 18-22
Author(s):  
Yan Shuang Zhang ◽  
Yu Jun Zhang ◽  
Teng Li ◽  
Qi Song Li
Keyword(s):  
Single Phase ◽  
Combustion Method ◽  
Yttrium Nitrate ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
Powder Morphology ◽  
X Ray ◽  
Calcination Temperatures ◽  
Yttrium Acetate

Nanocrystalline yttria powders were successfully synthesized by microwave-induced solution combustion method using a binary yttrium salt system with yttrium nitrate as oxidant and yttrium acetate as reductant. The process involved the redox reaction between the two yttrium salt under the heat generated by absorbing microwaves. The prepared powders were characterized by X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to study the structure and powder morphology. The prepared powders were indicated to exhibit single-phase cubic crystalline yttria structure. The oxidant/reductant ratios and the calcination temperatures had an effect upon the particle size and powder morphology. The size of the crystallites varied in the range of 16 nm~27 nm with different reductant proportion. The powders were observed to show loosely agglomerated fractals.

Dielectric Behavior and A. C. Conductivity Studies on Nickel Nanoferrites Synthesized by Solution Combustion Method

2012 ◽  
Vol 584 ◽  
pp. 299-302 ◽  
Author(s):  
B.J. Madhu ◽  
V. Jagadeesha Angadi ◽  
H. Mallikarjuna ◽  
S.O. Manjunatha ◽  
B. Shruthi ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Room Temperature ◽  
Combustion Method ◽  
Dielectric Behavior ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
X Ray ◽  
Wide Range ◽  
Hopping Model

Nanoscale Nickel ferrite particles were prepared by combustion method using nickel nitrate as oxidizer and urea as a fuel. The structure of the sample is studied with X-ray diffraction (XRD) using Cu-Kα radiation. The X-ray diffraction analysis revealed the nanocrystalline nature in the prepared ferrite samples. Dielectric studies have been undertaken over a wide range of frequencies (100Hz-5MHz) for Nickel nanoferrites at room temperature. Dielectric properties such as dielectric loss tangent (D), dielectric constant (ε′ ) and dielectric loss factor (ε″) are found to decrease with the increase in the frequency. Observed variations are understood on the basis of Koop’s phenomenological model. Further, a. c. conductivity of the Nickel nanoferrite was found to increase with the increase in the frequency. Observed variation in the a. c. conductivity with the frequency has been understood on the basis of electron hopping model.

LiNi0.5Mn1.5O4 Prepared by a Solution Combustion Synthesis at Different Temperatures

2011 ◽  
Vol 186 ◽  
pp. 3-6
Author(s):  
Gui Yang Liu ◽  
Jun Ming Guo ◽  
Bao Sen Wang
Keyword(s):  
Electrochemical Performance ◽  
Single Phase ◽  
Solution Combustion Synthesis ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
X Ray ◽  
Different Temperatures ◽  
Micro Morphology

LiNi0.5Mn1.5O4 powders have been prepared by a solution combustion method at 300-800oC. X-ray diffraction (XRD) and scanning electric microscope (SEM) were used to determine the phase composition and micro morphology of the products. The results indicate that the products with single phase LiNi0.5Mn1.5O4 can be obtained at 400-600oC. The electrochemical performance was tested by a coin-type battery. The product prepared at 600oC has the best electrochemical performance. The maximum capacity of the product prepared at 600oC is 135mAh/g at the current density of 30mA/g, and after 30 cycles, the capacity fades little.

Sign in / Sign up

Export Citation Format

Share Document