Recyclable Heterogeneous Fe-Mo Nanocatalyst: Application in Solvent Free Synthesis of β-enaminones

2019 ◽  
Vol 6 (3) ◽  
pp. 238-247
Author(s):  
Swapnil R. Bankar
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Significant Loss ◽  
Solvent Free ◽  
Catalyst Loading ◽  
Spectroscopic Techniques ◽  
Impregnation Method ◽  
Molybdenum Catalyst ◽  
X Ray ◽  
Solvent Free Condition

<P>Background: In recent years, green organic transformation has become a challenge for a chemist in areas like social sector, health, and environment. Literature survey revealed that a nano magnetite supported heterogeneous catalysis is an emergent field with huge application in chemical synthesis. </P><P> Objective: In the present article, the aim was to develop a simple and facile method to carry organic reaction under benign media. So, the focus was on the synthesis of nano-magnetite supported molybdenum catalyst and its application in β-enaminones synthesis. </P><P> Methods: Magnetically recyclable heterogeneous ferrite-molybdenum catalyst was prepared by simple impregnation method. The synthesized nanocatalyst Fe-Mo was well analysed by spectroscopic techniques like X-ray diffraction analysis, X-ray photoelectron spectroscopy, transmission electron microscopy, field-emission gun scanning electron microscopy and vibrating-sample magnetometry. The functionalized nanocatalyst Fe-Mo was employed in the synthesis of β-enaminones under solvent free condition. </P><P> Results: The competency of synthesized nanocatalyst-Fe-Mo was observed to be good for the synthesis of β-enaminones derivatives under microwave irradiation and gave excellent yield (86-96%) of the product. The catalyst was recycled for more than five consecutive runs without significant loss in its activity. </P><P> Conclusion: In the present research article, synthesis of highly active, magnetically recyclable Fe- Mo nanocatalyst was obtained from easily available precursor. The MNP was stable under investigated conditions and effective in β-enaminones synthesis. The simple eco-friendly method, low catalyst loading, short transformation time, and reusability of the catalyst thoroughly follow the sustainable protocol.</P>

scholarly journals FeNiCeOx ternary catalyst prepared by ultrasonic impregnation method for diclofenac removal in Fenton-like system

2019 ◽  
Vol 79 (9) ◽  
pp. 1675-1684 ◽  
Author(s):  
Guang Xian ◽  
Nan Zhang ◽  
Guangming Zhang ◽  
Yi Zhang ◽  
Zhiguo Zou
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Hot Spot ◽  
Catalytic Performance ◽  
Synthesis Process ◽  
Impregnation Method ◽  
Lattice Contraction ◽  
X Ray ◽  
Ultrasonic Synthesis ◽  
Cavitation Effect

Abstract FeNiCeOx was firstly prepared by ultrasonic impregnation method and used to remove diclofenac in a Fenton-like system. The catalytic activity was improved successfully by doping Ni into FeCeOx. The diclofenac removal efficiency reached 97.9% after 30 min reaction. The surface morphology and properties of FeNiCeOx were characterized by Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Raman and X-ray photoelectron spectroscopy (XPS) analyses. FeNiCeOx in this paper had larger specific surface area than those prepared by other methods, which was attributed to the cavitation effect and hot-spot effect during the ultrasonic synthesis process. Low crystallinity of Fe2O3 and NiO showed by characterization could lead to high interaction of Fe and Ni ions with support of CeO2. They substituted Ce in CeO2, caused lattice contraction and formed more oxygen vacancies, which favoured the catalytic reaction. Meanwhile, Fe and Ce ions both had redox cycles of Fe3+/Fe2+ and Ce4+/Ce3+, which facilitated the electron transfer in the reaction. The synergistic effect among Fe, Ni and Ce might lead to better catalytic performance of FeNiCeOx than any binary metal oxides constituted from the above three elements. Finally, the potential mechanism of diclofenac removal in FeNiCeOx-H2O2 system is proposed.

Platinum Reduction Study on Pt/C Electro-catalysts for PEMFC

2013 ◽  
Vol 16 (3) ◽  
pp. 141-145
Author(s):  
M.L. Hernandez-Pichardo ◽  
R. Gonzalez-Huerta ◽  
P. del Angel ◽  
E. Palacios-Gonzalez ◽  
M. Tufiño-Velazquez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Reducing Agents ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Conditions ◽  
Platinum Species ◽  
Scanning Electron

Platinum reduction on Pt/C catalysts was studied on samples prepared by the impregnation method using different Pt precursors and reducing agents such as ethanol, sodium borohydride and ethanol-UV light (photo-assisted reduction), in order to compare the efficiency of the different reducing agents. The influence of the reduction level of the platinum species on the electrochemical behavior of these catalysts has been determined. The catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and linear and cyclic voltammetry. The results show that the reduction level depends mainly on the platinum precursor. Moreover, it was found that the higher electrochemical activity was found using catalysts reduced with ethanol, whereas by using NaBH4 as the reducing agent, the total reduction of the platinum precursor is very difficult in same synthesis conditions. The analysis of the XPS results shows that samples reduced with ethanol presented the lower PtOx/Pt reduction ratio.

scholarly journals Sulfur resistance of Ce-Mn/TiO 2 catalysts for low-temperature NH 3 –SCR

2018 ◽  
Vol 5 (3) ◽  
pp. 171846 ◽  
Author(s):  
Quan Xu ◽  
Wenjing Yang ◽  
Shitong Cui ◽  
Jason Street ◽  
Yan Luo
Keyword(s):  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
Conversion Rate ◽  
Active Sites ◽  
Sol Gel ◽  
Textural Properties ◽  
Catalyst Loading ◽  
Impregnation Method ◽  
No Conversion ◽  
X Ray

Ce-Mn/TiO 2 catalyst prepared using a simple impregnation method demonstrated a better low-temperature selective catalytic reduction of NO with NH 3 (NH 3 –SCR) activity in comparison with the sol-gel method. The Ce-Mn/TiO 2 catalyst loading with 20% Ce had the best low-temperature activity and achieved a NO conversion rate higher than 90% at 140–260°C with a 99.7% NO conversion rate at 180°C. The Ce-Mn/TiO 2 catalyst only had a 6% NO conversion rate decrease after 100 ppm of SO 2 was added to the stream. When SO 2 was removed from the stream, the catalyst was able to recover completely. The crystal structure, morphology, textural properties and valence state of the metals involving the novel catalysts were investigated using X-ray diffraction, N 2 adsorption and desorption analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive spectroscopy, respectively. The decrease of NH 3 –SCR performance in the presence of 100 ppm SO 2 was due to the decrease of the surface area, change of the pore structure, the decrease of Ce 4+ and Mn 4+ concentration and the formation of the sulfur phase chemicals which blocked the active sites and changed the valence status of the elements.

scholarly journals Study on Hydrogenation Performance of Oil-Soluble Molybdenum Catalyst in Coal-Oil Co-Processing

2022 ◽  
Author(s):  
Guangyao Wang ◽  
Xiqian Wang ◽  
Yuan Zhao
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Heavy Fraction ◽  
X Ray Diffraction ◽  
Molybdenum Catalyst ◽  
X Ray ◽  
Transmission Electron ◽  
Novel Method ◽  
Scanning Electron

Abstract An oil-soluble molybdenum catalyst was synthesized by a simple and novel method and studied for hydrogenation in coal-oil co-processing. The catalyst was characterized by infrared spectrum (IR), thermogravimetry (TG), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The morphology and crystal structure of catalyst was characterized with scanning electron microscope (SEM) and high resolution transmission electron microscopy (HRTEM). The catalyst can be considered as a precursor that can be converted into active MoS2 components through thermal decomposition and sulfidation. The hydrogenation experiment was carried out by the model reactants of tetradecane and 2-methylnaphthalene with a change of reaction (405℃-445℃) temperature and concentrations of molybdenum catalyst (Mo conc. 0.6-10 mg/g), and results showed that the delightly hydrogenation function of catalyst is to improve the saturation of aromatic ring. The most abundant stacking numbers of decomposed catalyst were 2 and 3, accounting for 53% of all catalyst microcrystalline units. The rapid hydrogenation stage and the significant decrease of feed heavy fraction in co-processing experiment provided the evidence that the hydrogenation performance of the synthesized catalyst is remarkable in coal-oil co-processing.

scholarly journals Nanostructured Materials for Food Applications: Spectroscopy, Microscopy and Physical Properties

2019 ◽  
Vol 6 (1) ◽  
pp. 26 ◽  
Author(s):  
Shubham Sharma ◽  
Swarna Jaiswal ◽  
Brendan Duffy ◽  
Amit Jaiswal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nanostructured Materials ◽  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
Nanostructured Material ◽  
Correlation Spectroscopy ◽  
Spectroscopic Techniques ◽  
X Ray ◽  
Transmission Electron

Nanotechnology deals with matter of atomic or molecular scale. Other factors that define the character of a nanoparticle are its physical and chemical properties, such as surface area, surface charge, hydrophobicity of the surface, thermal stability of the nanoparticle and its antimicrobial activity. A nanoparticle is usually characterized by using microscopic and spectroscopic techniques. Microscopic techniques are used to characterise the size, shape and location of the nanoparticle by producing an image of the individual nanoparticle. Several techniques, such as scanning electron microscopy (SEM), transmission electron microscopy/high resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM) and scanning tunnelling microscopy (STM) have been developed to observe and characterise the surface and structural properties of nanostructured material. Spectroscopic techniques are used to study the interaction of a nanoparticle with electromagnetic radiations as the function of wavelength, such as Raman spectroscopy, UV–Visible spectroscopy, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), dynamic light scattering spectroscopy (DLS), Zeta potential spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray photon correlation spectroscopy. Nanostructured materials have a wide application in the food industry as nanofood, nano-encapsulated probiotics, edible nano-coatings and in active and smart packaging.

scholarly journals Preparation of Functionalized Superparamagnetic Fe3O4@Dopamine@Metal Ions (Cu+,Ru2+) Nanocomposites and its Catalytic Applications

2020 ◽  
Author(s):  
Renuka Singh ◽  
Shukla Majhi ◽  
Keshav Sharma ◽  
Mohd. Ali ◽  
Chandra Shekhar Pati Tripathi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Metal Ions ◽  
Photoelectron Spectroscopy ◽  
Reaction Medium ◽  
Significant Loss ◽  
Transfer Hydrogenation ◽  
Simple Method ◽  
Catalytic Systems ◽  
X Ray ◽  
Catalytic Applications

<p>In this work, we present a simple method for the synthesis of metal ions stabilized on dopamine modified iron oxide nanoparticles (Fe<sub>3</sub>O<sub>4</sub>@DA@M<sup>x+</sup>) and their catalytic applications in important organic transformation reactions. Two different metal ions (Cu<sup>+1</sup> and Ru<sup>2+</sup>) are studied in this work. It is observed that both synthesized Fe<sub>3</sub>O<sub>4</sub>@DA@Cu<sup>+ </sup>and Fe<sub>3</sub>O<sub>4</sub>@DA@Ru<sup>2+ </sup>can effortlessly be separated from the reaction medium by positioning an external magnetic field. Dopamine, which is used as an anchor between Fe<sub>3</sub>O<sub>4</sub> and metal ions, increases the solubility of catalyst in reaction medium and prevents leaching of metal ions from the catalyst surface. Here Fe<sub>3</sub>O<sub>4</sub>@DA@Cu<sup>+ </sup>is used in the synthesis of 1,2,3-triazole derivatives via azide-alkyne cycloaddition reactions and Fe<sub>3</sub>O<sub>4</sub>@DA@Ru<sup>2+ </sup>is used for transfer hydrogenation reaction of various aryl ketones. The Fe<sub>3</sub>O<sub>4</sub>@DA@M<sup>x+</sup> nanocomposite is characterized via powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA) and vibrating-sample magnetometer (VSM). The Fe<sub>3</sub>O<sub>4</sub>@DA@M<sup>x+</sup> catalytic systems can be reused in the reaction mixture up to five times without significant loss in their catalytic activity.</p>

scholarly journals Palladium Nanocatalysts on Hydroxyapatite: Green Oxidation of Alcohols and Reduction of Nitroarenes in Water

2019 ◽  
Vol 9 (19) ◽  
pp. 4183 ◽  
Author(s):  
Shokouhimehr ◽  
Yek ◽  
Nasrollahzadeh
Keyword(s):  
Electron Microscopy ◽  
Heterogeneous Catalyst ◽  
Photoelectron Spectroscopy ◽  
Pd Nanoparticles ◽  
Structural Features ◽  
Significant Loss ◽  
X Ray ◽  
Transmission Electron ◽  
Palladium Nanocatalysts ◽  
High Yields

A green procedure is described for supporting Pd nanoparticles on hydroxyapatite (HAP), which serves as a highly-stable heterogeneous catalyst displaying excellent activity for the aqueous expeditious reduction of nitroaromatics to the corresponding amines with sodium borohydride, and oxidation of primary and secondary alcohols by hydrogen peroxide with high yields and selectivities. The structural features of the prepared catalyst are confirmed by latest techniques including field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The reusability of the heterogeneous catalyst was affirmed in the aqueous reduction of nitrobenzene and oxidation of cycloheptanol for six consecutive runs without significant loss of catalytic activity.

MoO2 Formed on Mesoporous Graphene Oxide: Efficient and Stable Catalyst for Epoxidation of Olefins

2017 ◽  
Vol 70 (9) ◽  
pp. 1039 ◽  
Author(s):  
Gang Bian ◽  
Pingping Jiang ◽  
Kelei Jiang ◽  
Yirui Shen ◽  
Linggang Kong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Mesoporous Structure ◽  
Carbon Chain ◽  
Catalytic Performance ◽  
Significant Loss ◽  
X Ray ◽  
Novel Catalyst

A novel mesoporous MoO2 composite supported on graphene oxide (m-MoO2/GO) has been designed and applied as an efficient epoxidation catalyst. The m-MoO2/GO composite was characterised by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmet–Teller surface area analysis, field emission scanning electron microscopy, and transmission electron microscopy. Compared with pure mesoporous MoO2 (m-MoO2) and amorphous MoO2-graphene oxide (a-MoO2/GO), m-MoO2/GO exhibits the best catalytic activity. The conversion and selectivity for cyclooctene are both over 99 % in 6 h. Remarkably, the mesoporous structure in m-MoO2/GO which derives from SiO2 nanospheres endows the catalyst better catalytic performance for long chain olefins: the conversion of methyl oleate can be as high as 82 %. Such a robust catalyst can be easily recycled and reused five times without significant loss of catalytic activity. This novel catalyst is promising in the synthesis of epoxides with a long carbon chain or large ring size.

Rapid Solvent-Free Melting Synthesis of Tungsten Nitrides with Lamellar, Solid Spherical Nanostructures at a Low Temperature

2012 ◽  
Vol 535-537 ◽  
pp. 314-318
Author(s):  
Wei Luo ◽  
Yan Tang ◽  
De Gang Ouyang ◽  
Bin Han ◽  
Ming Hui Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Transmission Electron ◽  
Tungsten Nitrides ◽  
Scanning Electron

A rapid solvent-free melting route has been successfully developed for the synthesis of tungsten nitrides with lamellar and solid spherical nanostructures which have considerably different surface areas (106.4 m2g-1contrast to 8.3 m2g-1) by the reaction of WCl6 and NaNH2 at 220 °C for 2-5 h directly, and it is found that the heat insulating property of reaction container plays important roles in the composition, phase, and morphologies of the nitrides. The products were analyzed by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). Their thermal stability and surface area were measured by thermogravimetric analysis (TGA) and BET, respectively. Finally, the possible formation mechanism of tungsten nitrides with different morphologies was also investigated.

scholarly journals A Highly Efficient Heterogeneous Catalyst of Bimetal-Organic Frameworks for the Epoxidation of Olefin with H2O2

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2389
Author(s):  
Fei Wang ◽  
Xiang-Guang Meng ◽  
Yan-Yan Wu ◽  
Hong Huang ◽  
Jing Lv ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Styrene Oxide ◽  
Significant Loss ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cyclic Olefins ◽  
Transmission Electron ◽  
Copper Component

A series of bimetel organic framework MnxCu1−x-MOF were prepared. The MOFs was characterized and analyzed by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The catalytic activity of the developed catalyst was tested on various olefins by H2O2 as oxidant. The MOFs catalyst exhibits excellent catalytic activity for the epoxidations of various aromatic and cyclic olefins. Particularly, Mn0.1Cu0.9-MOF can achieve 90.2% conversion of styrene with 94.3% selectivity of styrene oxide at 0 °C after reaction 6 h. The MOF exhibited the catalytic activity of inverse temperature effect on epoxidation of styrene. The introduction of copper component can stabilize H2O2 and inhibit its decomposition to a certain extent. The catalyst can be reused at least five cycles without significant loss in activity towards epoxidation.

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