Preparation of CuO/γ-Al2O3 Catalysts by Impregnationin Supercritical CO2

2011 ◽  
Vol 396-398 ◽  
pp. 1313-1317
Author(s):  
Li Min Li ◽  
San Kui Xu ◽  
Xiao Dong Wang ◽  
Nan Nan Guo ◽  
Yun Lai Su ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Xrd Analysis ◽  
Catalyst Preparation ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impregnation Time ◽  
Temperature And Pressure ◽  
Organometallic Precursors ◽  
Adsorption Quantity

CuO/γ-Al2O3 catalysts were prepared by supercritical CO2 (SC-CO2) impregnation method. The preparation was carried out in SC-CO2 with Cu(NO3)2 as precursor, methanol as assistant solvent, and γ-Al2O3 as support. The effects of impregnation parameters such as temperature and pressure of SC-CO2, impregnation time, ratio of precursor to support, and amount of assistant solvent on catalyst preparation were investigated. The as-prepared catalysts were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis and compared to that prepared by the conventional impregnation method. The SC-CO2 impregnation method provided higher adsorption rate, larger adsorption quantity, more homogeneous dispersion of precursor, and stronger interaction between precursor and support. The catalytic degradation of methylene blue (MB) was used as probe reaction to estimate the catalytic activity of two catalysts prepared by two methods. The catalyst prepared by SC-CO2 impregnation method exhibits significantly improved catalytic activity. These results show that the inorganic metallic reagents as precursor with assistant solvent can be used as an alternative for the organometallic precursors in SC-CO2 impregnation method.

Preparation of Chrysotile Nanotubes under Hydrothermal Condition

2011 ◽  
Vol 284-286 ◽  
pp. 688-691 ◽  
Author(s):  
Yang Feng Huang ◽  
Ye Bin Cai ◽  
Hao Liu
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Condition ◽  
Xrd Analysis ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Inner Diameter ◽  
Temperature And Pressure

In a neutral environment, Chrysotile nanotubes have been synthesized by hydrothermal method, with MgO and SiO2powder as the starting materials. X-Ray Diffraction(XRD), Scanning Electron Microscopy(SEM), Transmission Electron Microscopy(TEM) are used to characterize the crystal structure and morphology of the as-prepared samples. We found that the diameter of Chrysotile is uniform. Their outer diameter is about 30~50 nm and the inner diameter is about 6~8 nm. The length of them is a few hundred nanometers. The XRD analysis indicates that the as-prepared Chrysotile is a Rhombohedral structures. The results of HRTEM and SAED showed that the {006} planes of serpentine roll up along the [600] direction to form the tubular structure. In addition, the curves of temperature and pressure with time showed that the water might participate in the reaction.

Influence of the Formation of Aluminium Spinel, AlVO4, on the Catalytic Activity of V2O5 Supported on γ-Alumina

1994 ◽  
Vol 59 (9) ◽  
pp. 1983-1990 ◽  
Author(s):  
Mohamed M. M. Abd El-Wahab ◽  
Abd El-Aziz A. Said
Keyword(s):  
Electrical Conductivity ◽  
Catalytic Activity ◽  
Flow System ◽  
Sharp Decrease ◽  
Maximum Activity ◽  
Impregnation Method ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Activity

Vanadium pentoxide catalysts supported on γ-alumina (1 - 50 mole %) were prepared by impregnation method and calcined at 400 and 680 °C for 4 h. The structure of the original and calcined samples was characterized by DTA and X-ray diffraction. The electrical conductivity measurements of the calcined samples reveal that the conductance increases while the Fermi potential decreases on increasing V2O5 content up to 50 mole %. The catalytic dehydration of isopropanol was carried out at 250 °C using a flow system. The results showed an observable increase in the extent of catalytic dehydration of the alcohol on increasing V2O5 content from 5 mole % to 50 mole % with the samples calcined at 400 °C. The catalysts calcined at 680 °C were found to exhibit maximum activity at the composition of 20 mole % V2O5. Above the maximum a sharp decrease in the conversion and the yield towards propylene was found due to formation of aluminium vanadate, i.e. AlVO4 spinel. The low activity associated with the existence of this spinel was correlated with the sharp decrease in the Fermi potential.

scholarly journals The catalytic oxidation of toluene at low temperature over palladium nanoparticles supported on Alumina sphere catalysts: effects of Palladium precursors and preparation method

2019 ◽  
Vol 21 (4) ◽  
pp. 48-50 ◽  
Author(s):  
Thien Huu Pham ◽  
Ha An Quoc Than ◽  
Ha Manh Bui
Keyword(s):  
Catalytic Activity ◽  
Gas Phase ◽  
Preparation Method ◽  
Catalyst Preparation ◽  
Palladium Chloride ◽  
Metal Dispersion ◽  
X Ray Diffraction ◽  
Wet Impregnation ◽  
X Ray ◽  
Transmission Electron

Abstract In this study, 1 wt.% Pd/Al2O3 sphere catalysts were prepared using the wet-impregnation (WI) and deposition-precipitation (DP) method using palladium chloride and tetraamminepalladium (II) nitrate as salt precursors. All catalysts were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier-transform infrared (FTIR) spectroscopy. The catalytic activity in toluene oxidation under gas-phase conditions was measured. The obtained results showed that metal dispersion and catalytic activity were strongly dependent on the salt precursor and method of catalyst preparation. The use of tetraamminepalladium (II) nitrate as the precursor presented smaller particle size, an enhanced dispersion and higher specific surface area. Moreover, the catalyst prepared with this precursor also showed higher catalytic activity than that prepared with palladium chloride. At 1 wt.% Pd loading, complete oxidation of toluene was achieved at 250°C. However, there was only approximately 80–90% efficient at the same temperature when the catalyst was prepared with palladium chloride as the precursor.

Green synthesis of CuO/rGO nanocomposite using Terminalia Arjuna bark extract and its catalytic activity for purification of water

2022 ◽  
Author(s):  
Vanita Kumari ◽  
Prit Pal Singh ◽  
Sandeep Kaushal
Keyword(s):  
Fourier Transform ◽  
Catalytic Activity ◽  
Xrd Analysis ◽  
Bark Extract ◽  
Terminalia Arjuna ◽  
X Ray Diffraction ◽  
Biogenic Synthesis ◽  
X Ray ◽  
Uv Visible ◽  
Purification Of Water

Biogenic synthesis of CuO/rGO nanocomposites was carried out successfully using Terminalia Arjuna bark extract. Various analytical methods such as UV-visible (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction (XRD) analysis, Field...

Oxidation of Acetaldehyde Over Cobalt Supported on Nanosized Carbon Black Catalysts

2021 ◽  
Vol 21 (7) ◽  
pp. 4029-4032
Author(s):  
Hyung-Sun Yoon ◽  
Seong-Gyu Seo
Keyword(s):  
Catalytic Activity ◽  
Carbon Black ◽  
Catalyst Surface ◽  
Catalyst Support ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Acetaldehyde Oxidation ◽  
X Ray ◽  
Loading Amount ◽  
Economic Considerations

In this study, we investigated the oxidation of acetaldehyde over Co/carbon black catalysts. All experiments were conducted in the temperature range of 200–440 °C, at an acetaldehyde concentration of 0.94 mol% in air, and using Co loading amounts in the range of 2–60 wt%. The nanosized carbon black and Co/carbon black catalysts were characterized using thermogravimetric analysis (TGA) and X-ray diffraction (XRD) analysis. The TGA data revealed that the nanosized carbon black was stable at high temperatures (600 °C), and the XRD results indicated that Co/carbon black was deteriorated and Co oxides, such as Co3O4, were formed. The addition of Co3O4 crystallites on the catalyst surface provided the greatest increase in catalytic activity. The catalytic activity of the supports used in this study for the acetaldehyde oxidation reaction increased as follows: SiO2 < TiO2 < carbon black < SiO2–Al2O3. The experimental results and economic considerations revealed that nanosized carbon black could be effectively used as catalyst support for the oxidation of acetaldehyde. The activity of the Co/carbon black catalysts varied with the Co loading amount, and the optimum Co loading amount was 10 wt%.

scholarly journals Influence of NiO/La2O3 Catalyst Preparation Method on Its Reactivity in the Oxy-Steam Reforming of LNG Process

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1174
Author(s):  
Magdalena Mosinska ◽  
Waldemar Maniukiewicz ◽  
Malgorzata I. Szynkowska-Jozwik ◽  
Pawel Mierczynski
Keyword(s):  
Catalytic Activity ◽  
Phase Composition ◽  
Steam Reforming ◽  
Preparation Method ◽  
Catalyst Preparation ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
X Ray ◽  
Activity Measurements ◽  
Temperature Programmed

The oxy-steam reforming of liquefied natural gas reaction (OSR-LNG) is promising process for syngas generation. In this paper, the catalytic properties of NiO/La2O3 systems prepared by wet impregnation and co-precipitation methods were extensively investigated in OSR-LNG reaction. The physicochemical properties of the studied catalytic materials were determined using various techniques including Temperature programmed reduction (TPR-H2), Temperature programmed desorption (TPD-NH3), Brunauer, Emmett and Teller (BET), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) with an energy dispersive X-Ray spectrometer (EDS). Reactivity measurements performed in the OSR-LNG process showed that the catalyst preparation method and the calcination temperature significantly affected the activity of NiO/La2O3 catalysts in the OSR-LNG reaction. The catalytic activity tests showed that NiO/La2O3 system prepared by a wet impregnation method and calcined at 700 °C showed the total conversion of the LNG component at 900 °C and the highest H2 yield at 700 and 900 °C. The phase composition studies confirmed the formation of the LaNiO3 structure in the case of the NiO/La2O3 catalyst prepared by wet impregnation, calcined at the temperature of 700 °C. Catalytic activity measurements showed that the reactivity of the catalysts was related to their phase composition and acidity. SEM images of spent catalysts showed that the smallest amount of carbon deposit was detected on the surface of the most active systems.

scholarly journals Synthesis of Graphene Oxide Enriched Natural Kaolinite Clay and Its Application For Biodiesel Production

2020 ◽  
Vol 10 (2) ◽  
pp. 307-315
Author(s):  
Syukri Syukri ◽  
Fadhil Ferdian ◽  
Yetria Rilda ◽  
Yulia Eka Putri ◽  
Mai Efdi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Potassium Hydroxide ◽  
Xrd Analysis ◽  
Bifunctional Catalyst ◽  
Biodiesel Production ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Activity Test

A heterogeneous catalyst is one type of catalyst which is very effective for biodiesel production; thus, in this study, a novel heterogeneous bifunctional catalyst was prepared by kaolinite clay obtained from Padang of West Sumatera and impregnated with graphene oxide and potassium hydroxide (KOH) for the simultaneous esterification and transesterification reactions of palm oil into biodiesel. For comparison, two other catalysts were also prepared. The first catalyst was the same clay which was heated at 450ºC for 4 hours, and the second catalyst was the same clay which was impregnated with potassium hydroxide (KOH) only. The three catalysts were characterized using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Fourier Transform Infra-Red (FTIR). XRF analysis showed that the clay sample’s main composition consisted of 54% silica, 35% alumina, and 7% hematite. The XRD analysis results showed that the most dominant crystal composition was quartz, kaolinite, and hematite. The analysis results using FTIR showed a change in intensity and shift in wave numbers indicating a cation exchange. The catalytic activity test was carried out with a ratio of oil and methanol 1:6, catalyst amount 5%, 60ºC reaction temperature, and 4 hours of reaction time.The results showed that the catalytic activity of clays impregnated with graphene oxide and potassium hydroxide was better with a yield of 58% compared to clays without impregnation and other clays that were only impregnated with KOH under the yields of 0.8% and 0.4%, respectively

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

Bis(μ-carboxylato)dienerhodium(I) Complexes - Synthesis, Characterization and Catalytic Activity

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1205-1221 ◽  
Author(s):  
Jiří Zedník ◽  
Jan Sedláček ◽  
Jan Svoboda ◽  
Jiří Vohlídal ◽  
Dmitrij Bondarev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Diffraction Analysis ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray

Dinuclear rhodium(I) η2:η2-cycloocta-1,5-diene (series a) and η2:η2-norborna-2,5-diene (series b) complexes with μ-RCOO- ligands, where R is linear C21H43 (complexes 1a, 1b), CH2CMe3 (2a, 2b), 1-adamantyl (3a, 3b) and benzyl (4a, 4b), have been prepared and characterized by spectroscopic methods. Structures of complexes 2b, 3a and 4a were determined by X-ray diffraction analysis. Complexes prepared show low to moderate catalytic activity in polymerization of phenylacetylene in THF giving high-cis-transoid polymers, but they show only oligomerization activity in dichloromethane.

A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

2021 ◽  
pp. 095441192199656
Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu
Keyword(s):  
Body Fluid ◽  
Xrd Analysis ◽  
Cold Isostatic Pressing ◽  
Expanded Perlite ◽  
X Ray Diffraction ◽  
Pressing Method ◽  
X Ray ◽  
Infra Red ◽  
Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

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