scholarly journals Copper-Containing Mixed Metal Oxides (Al, Fe, Mn) for Application in Three-Way Catalysis

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1344
Author(s):  
Tim Van Everbroeck ◽  
Radu-George Ciocarlan ◽  
Wouter Van Hoey ◽  
Myrjam Mertens ◽  
Pegie Cool
Keyword(s):  
Catalytic Activity ◽  
Spinel Structure ◽  
Mixed Oxides ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Application ◽  
Mixed Spinel ◽  
Co Precipitation ◽  
Three Way Catalysis

Mixed oxides were synthesized by co-precipitation of a Cu source in combination with Al, Fe or Mn corresponding salts as precursors. The materials were calcined at 600 and 1000 °C in order to crystallize the phases and to mimic the reaction conditions of the catalytic application. At 600 °C a mixed spinel structure was only formed for the combination of Cu and Mn, while at 1000 °C all the materials showed mixed spinel formation. The catalysts were applied in three-way catalysis using a reactor with a gas mixture containing CO, NO and O2. All the materials calcined at 600 °C displayed the remarkable ability to oxidize CO with O2 but also to reduce NO with CO, while the pure oxides such as CuO and MnO2 were not able to. The high catalytic activity at 600 °C was attributed to small supported CuO particles present and imperfections in the spinel structure. Calcination at 1000 °C crystallized the structure further which led to a dramatic loss in catalytic activity, although CuAl2O4 and CuFe2O4 still converted some NO. The materials were characterized by X-ray diffraction (XRD), Raman spectroscopy, H2-Temperatrue Programmed Reduction (H2-TPR), N2-sorption and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX).

Spinel Structured Iron Gallium Oxynitride - Fe2GaO2N2

2021 ◽  
Vol 1160 ◽  
pp. 45-50
Author(s):  
Savitha Kadencheri Unnikrishnan
Keyword(s):  
Magnetic Properties ◽  
Chemical Composition ◽  
Spinel Structure ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Novel Material ◽  
Optical And Magnetic Properties ◽  
Co Precipitation

A facile method was successfully developed to prepare Ternary oxynitride of iron and gallium. Initially mixed oxyhydroxides of Iron and gallium were prepared by co-precipitation method. Then this was nitrided using urea and agar in presence of ammonia at 900°C, which gave mixed cation oxynitride . This mixed oxynitride was characterized using XRD, XPS and SEM. The X-ray diffraction pattern of the Fex’GaxOyNz phase was refined within the cubic spinel structure (space group Fd-3m), using the fullprof program. On assuming 3+ oxidation state for half of iron and whole of gallium, the chemical composition of the oxynitride spinel determined by the X-ray analysis is Fe2GaN2O2. The refinement using these parameters resulted in a good fit to the observed diffraction data, with a crystallographic R factor of 5.92. This ternary oxynitride of iron and gallium is a novel material which can give unique optical and magnetic properties.

scholarly journals Effect of Sulfation on Zirconia-Pillared Montmorillonite to the Catalytic Activity in Microwave-Assisted Citronellal Conversion

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Is Fatimah ◽  
Dwiarso Rubiyanto ◽  
Thorikul Huda
Keyword(s):  
Catalytic Activity ◽  
Surface Acidity ◽  
Total Pore Volume ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Microwave Assisted ◽  
Tandem Cyclization

Preparation of sulfated zirconia-pillared montmorillonite was carried out in two steps; zirconia pillarization and sulfation to zirconia-pillared montmorillonite. The prepared materials were characterized by using X-ray diffraction (XRD), measurement of the specific surface area, total pore volume and pore size distribution by the N2adsorption method, scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and surface acidity determination by using pyridine adsorption-FTIR analysis. The activity of the materials as catalysts was evaluated for a microwave-assisted conversion of citronellal. The results showed that the prepared materials had a physicochemical character that promoted high catalytic activity to convert citronellal. From varied Zr content and study of the effect of sulfation on the activity, it was found that Zr content and sulfation increase the surface acidity of the material as shown by the higher total conversion and tendency to produce menthol as a product of the tandem cyclization-hydrogenation mechanism.

scholarly journals Syntheses and Thermal Characterisation of Mixed (Sm-Y) Oxalates Prepared by Coprecipitation Method

2011 ◽  
Vol 8 (1) ◽  
pp. 113-117
Author(s):  
Presenjit Pauri ◽  
S. K. Ghoshal ◽  
H. S. Tewari
Keyword(s):  
Solid Solution ◽  
Thermal Decomposition ◽  
Thermal Treatment ◽  
Differential Scanning Calorimeter ◽  
Mixed Oxides ◽  
Xrd Analysis ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation

In this work, mixed (Sm1-xYx)2[C2O4]3.nH2O with x= 0.50 and 0.70 were prepared using standardized co precipitation method. All the synthesized oxalates were characterized by x-ray diffraction and differential scanning calorimeter. All the samples are homogeneous in stoichiometry. The XRD analysis of these synthesized samples reveals that a solid solution forms for these two compositions The thermal decomposition of the mixed oxalates is complex although completed a lower temperatures. This is an important result for the preparation of Sm-Y mixed oxides, because all the properties of the mixed oxides are intrinsic and depend only on their composition and thermal treatment schedules.

scholarly journals FSM-16-SO3H nanoparticles as a novel heterogeneous catalyst: preparation, characterization, and catalytic application in the synthesis of polyhydroquinolines

2018 ◽  
Vol 41 (3-4) ◽  
pp. 91-101 ◽  
Author(s):  
Somayeh Hashemi-Uderji ◽  
Mohammad Abdollahi-Alibeik ◽  
Reza Ranjbar-Karimi
Keyword(s):  
Room Temperature ◽  
Ammonium Acetate ◽  
Sol Gel ◽  
Ethyl Cyanoacetate ◽  
Textural Properties ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Catalytic Application

Abstract FSM-16-SO3H nanoparticles were prepared using a sol-gel method at room temperature. The prepared FSM-16-SO3H was used to catalyze the synthesis of polyhydroquinolines through a one-pot, four-component reaction of aldehydes, dimedone, ethyl cyanoacetate, and ammonium acetate under reflux condition in EtOH as a green solvent. To investigate the textural properties of the prepared catalyst, various techniques were applied such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, and Brunauer–Emmett–Teller. High catalytic activity, easy handling, and thermal stability are the superior properties that could be denoted after successive investigations of this catalyst. In addition, the catalyst can be recovered easily and reused effectively for several cycles.

New organic–inorganic hybrid compounds based on [SiNb12V2O42]12− with high catalytic activity for styrene epoxidation

2017 ◽  
Vol 4 (8) ◽  
pp. 1397-1404 ◽  
Author(s):  
Ting-Ting Zhang ◽  
Xiao Zhang ◽  
Ying Lü ◽  
Guo-Dong Li ◽  
Li-Na Xiao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
High Catalytic Activity ◽  
Styrene Epoxidation ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Hybrid Compounds

A series of new organic–inorganic hybrid compounds based on [SiNb12V2O42]12− have been obtained under hydrothermal conditions and characterized by IR, XRD, and single crystal X-ray diffraction analysis.

Preparation of Cobalt Phthalocyanine Supported Mg-Al Hydrotalcite and its Catalytic Activity for Degradation of Methylene Blue

2017 ◽  
Vol 748 ◽  
pp. 433-437
Author(s):  
Meng Xia Qian ◽  
Jian Li Ma ◽  
Min Hong Xu
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Supported Catalyst ◽  
Water Soluble ◽  
Precipitation Method ◽  
High Catalytic Activity ◽  
Catalytic Application ◽  
Ft Ir ◽  
Supporting Material ◽  
Co Precipitation

A novel supported catalyst is prepared through immobilization of water soluble phthalocyanine, which is synthesized by modifying tetraminophthalocyanine with cyanuric chloride, onto the supporting material Mg-Al hydrotalcite via co-precipitation method. The structure of the catalyst is characterized by infrared spectroscopy instrument (FT-IR) and X-ray diffractometer. Catalytic activity is examined through comparative experiments. The results show that it exhibits high catalytic activity for degradation of methylene blue (MB) in the presence of H2O2, the remaining rate of MB is 12.02% after 6 h. The reaction process conforms to the equation of pseudo-first-order kinetics, and the correlation coefficient R2> 0.99. The recycling tests for five times are also carried out and prove its reusability in catalytic application.

Magnetically recyclable silica-coated magnetite-molybdate nanocatalyst and its applications in N-formylation reactions under solvent-free conditions-

2022 ◽  
Vol 19 ◽  
Author(s):  
Runjhun Tandon ◽  
Shripad Patil ◽  
Nitin Tandon ◽  
Pushpendra Kumar
Keyword(s):  
Catalytic Activity ◽  
Solvent Free ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
Co Precipitation ◽  
Coated Nanoparticle ◽  
Scanning Electron

Abstract: A novel magnetite silica-coated nanoparticle-supported molybdate nanocatalyst has been prepared successfully by a simple co-precipitation method. Prepared nanocatalyst has been characterized by different techniques like Fourier Transmission Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM) and Energy Dispersive X-ray Spectroscopy (EDX). Further, the catalytic activity of the nanocatalyst was explored for N-formylation reactions under solvent-free conditions. Interestingly, the catalyst could be reused for 10 cycles and only 2 mol % of the catalyst was sufficient to catalyze the N-formylation reaction at 700C under solvent-free conditions.

STRUCTURE, MORPHOLOGICAL, MAGNETIC AND OPTICAL PROPERTIES OF CuxMg1-xFe2O4 (x = 0, 0.5, 1) NANO FERRITES SYNTHESIZED BY CO-PRECIPITATION METHOD

2021 ◽  
pp. 46-54
Author(s):  
Chinh
Keyword(s):  
Saturation Magnetization ◽  
Spinel Structure ◽  
Single Phase ◽  
Secondary Phase ◽  
Ferromagnetic Material ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Patterns ◽  
Co Precipitation

CuxMg1.xFe2O4 nanoparticles were successfully synthesized by co-precipitation. The samples were calcined at 900 oC for 3 h and X-ray diffraction analysis showed that Cu0.5Mg0.5Fe2O4 had a single phase cubic spinel structure, while formation of secondary phase of Fe2O3 was observed in XRD patterns of CuFe2O4, MgFe2O4. The saturation magnetization (Ms) of Cu0.5Mg0.5Fe2O4 is in between the saturation magnetization values of CuFe2O4 and MgFe2O4 nanoparticles, CuFe2O4 is a ferromagnetic material, while MgFe2O4 and Cu0.5Mg0.5Fe2O4 show superparamagnetic behavior. The synthesized spinel ferrites were fully characterized using scanning electron microscopy (SEM), FTIR spectroscopy, energy dispersive spectroscopy (EDS) and UV-vis spectrophotometry.

scholarly journals A study on the synthesis of MIL-100(Fe) and its application in the catalytic degradation of methylene blue

2018 ◽  
Vol 1 (T5) ◽  
pp. 149-157
Author(s):  
Thien Vinh Tran ◽  
Dien Huu Huynh
Keyword(s):  
Methylene Blue ◽  
Fourier Transform ◽  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Hydrothermal Process ◽  
Catalytic Degradation ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

In the present paper, a study on the synthesis of MIL-100(Fe) by hydrothermal process and its application in the catalytic degradation of methylene blue (MB) was demonstrated. The obtained samples were characterized by X-ray Diffraction (XRD), scaning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), Brunauer, Emmett and Teller (BET) and energy-dispersive X-ray spectroscopy (EDX). The results showed that the synthesized MIL- 100(Fe) exhibited high crystallinity and surface area. Its catalytic activity was evaluated by measuring the rate of conversion of MB after oxidation reaction by H2O2. The results indicated that the MIL-100(Fe) showsed high catalytic activity for the oxidation reaction of MB and at pH = 10, MB was degraded almost completely after after 3 hours of presence of the catalyst.

Synthesis and Characterization of Ni/Mg/Al Mixed Oxides Obtained by Co-precipitation

2012 ◽  
Vol 1372 ◽  
Author(s):  
G. Martínez-Lozano ◽  
T. Kryshtab ◽  
M. Hesiquio Garduño ◽  
A. Kryvko
Keyword(s):  
Mixed Oxides ◽  
Xrd Analysis ◽  
Diffraction Peak ◽  
Precipitation Method ◽  
Particle Sizes ◽  
Extended Defects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation

ABSTRACTNi/Mg/Al mixed oxides were obtained from hydrotalcite-like precursors by thermal decomposition at 400º, 600º and 800ºC using co-precipitation method at pH 7. The mixed oxides were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS) techniques. XRD analysis revealed the formation of NixMg1-xO (x = 0 - 1), α-Al2O3 and traces of MgAl2O4 (NiAl2O4) phases. The diffraction peak positions for MgO or NiO oxides were shifted towards 2θ values higher than simulated for pure bulk oxides that can be attributed to the possible presence of lattice vacancies or surface compressive stress. The evaluated grain size by XRD technique was about 8 -10 nm. It was also detected the presence of microstrains that can be associated with the presence of extended defects in the grains. SEM observations showed that the particles of oxides are formed as agglomerates with the particle sizes of 50 nm up to 200 nm. EDS detected the presence of Mg2+, Ni2+, and Al3+ cations and oxygen in all particles independently on their size. The obtained results revealed the presence of mixture of Ni/Mg/Al oxides in each particle obtained. The oxides calcined at temperatures of 400º and 600ºC were unstable and under air storage they revert to the precursor. The incorporation of Ni2+ in Mg-Al mixed oxides leads to stability of the compounds calcined at 800ºC.

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