scholarly journals A Simple Method of Preparation of High Silica Zeolite Y and Its Performance in the Catalytic Cracking of Cumene

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Zhanjun Liu ◽  
Chenxi Shi ◽  
Dan Wu ◽  
Shixuan He ◽  
Bo Ren
Keyword(s):  
Zeolite Y ◽  
Sodium Aluminate ◽  
Crystallization Time ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Surface Areas ◽  
Xrf Scanning ◽  
High Silica ◽  
Adsorption Desorption

A series of high silicon zeolites Y were prepared through direct synthetic method by using silica sol as the silicon source and sodium aluminate as the aluminum source. The effects of alkalinity and crystallization time of the process of synthesis were investigated. To separately reveal the crystalline structure, element content, morphology, and surface areas, the as-synthesized zeolite Y was characterized by powder X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and N2adsorption-desorption isotherms (BET). The results show the as-synthesized zeolite Y with high relative crystallization and uniform morphology; the SiO2/Al2O3ratio was about 4.54~6.46. For an application, the zeolite cracking activity was studied with cumene as the probe molecules.

Structural and surface aspects of thermally treated copper aluminium mixed hydroxides

1991 ◽  
Vol 69 (10) ◽  
pp. 1511-1515 ◽  
Author(s):  
Awad I. Ahmed ◽  
S. E. Samra ◽  
S. A. El-Hakam
Keyword(s):  
Pore Structure ◽  
Copper Content ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Structure Surface ◽  
Adsorption Desorption

CuO–Al2O3 catalysts containing various amounts of copper oxide have been prepared by precipitation. The phase changes were studied by X-ray diffraction. The results obtained revealed that the thermal treatment of solid CuO–Al2O3 at 700 °C produced only crystalline CuO. Heating to 900 °C led to the formation of copper alumina spinel together with unreacted CuO and γ-Al2O3. The spinel content was found to increase with increasing copper content. Nitrogen adsorption–desorption isotherms on the calcined samples have been measured. Surface areas have been calculated and the pore structure analysed. The textural properties of the system were found to depend on both the copper content and the calcination temperature. Key words: CuO, Al2O3 catalysts, structure, surface area, pore structure.

scholarly journals Simple Solvothermal Approach to Highly Nanostructured Hematite Thin Films

2020 ◽  
Author(s):  
Casey M. Platnich ◽  
Jachym Slaby ◽  
David O'Connell ◽  
Simon Trudel
Keyword(s):  
Thin Films ◽  
Precursor Solution ◽  
Photoelectrochemical Cells ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Surface Areas ◽  
Nucleation Sites ◽  
Synthetic Procedure

<div>In this work, we present a solvothermal method for the synthesis of hematite thin films on fluorine-doped tin oxide</div><div>substrates. This simple method uses a precursor solution of iron(III) 2,4-pentanedionate dissolved in ethanol with a</div><div>microliter-scale amount of water and yields hematite ~ 500-nm thick films after annealing. The synthesised films</div><div>were characterised using an array of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance, and powder x-ray diffraction. Incorporating water into the precursor solution provides nucleation sites for the reaction and results show that by altering the amount of water used in the synthesis, it is possible to generate nanocrystalline films of different morphologies, nanocrystal size distributions, and surface areas. This synthetic procedure therefore provides control over the films’ physical and electrochemical characteristics. Doping of hematite thin films is also possible using this synthesis, as exemplified by doping with tin by adding tin(II) 2,4-pentanedionate to the precursor solution. To demonstrate utility, we build prototype photoelectrochemical cells using the synthesized hemtatite as the photoanode.</div>

scholarly journals Simple solvothermal approach to highly nanostructured hematite thin films

2020 ◽  
Author(s):  
Casey M. Platnich ◽  
Jachym Slaby ◽  
David O'Connell ◽  
Simon Trudel
Keyword(s):  
Thin Films ◽  
Precursor Solution ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Surface Areas ◽  
Nucleation Sites ◽  
Synthetic Procedure ◽  
Oxide Substrates

In this work, we present a solvothermal method for the synthesis of hematite thin films on fluorine-doped tin oxide substrates. This simple method uses a precursor solution of iron(III) 2,4-pentanedionate dissolved in ethanol with a microliter-scale amount of water and yields hematite ~ 500-nm thick films after annealing. The synthesised films were characterised using an array of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance, and powder x-ray diffraction. Incorporating water into the precursor solution provides nucleation sites for the reaction and results show that by altering the amount of water used in the synthesis, it is possible to generate nanocrystalline films of different morphologies, nanocrystal size distributions, and surface areas. This synthetic procedure therefore provides control over the films’ physical and electrochemical characteristics. Doping of hematite thin films is also possible using this synthesis, as exemplified by doping with tin by adding tin(II) 2,4-pentanedionate to the precursor solution. To demonstrate utility, we build prototype photoelectrochemical cells using the synthesized hemtatite as the photoanode.

Study of the catalytic activity of Al-Fe pillared clays in the Baeyer–Villiger oxidation

Clay Minerals ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. 275-284 ◽  
Author(s):  
L. S. Belaroui ◽  
A. Bengueddach
Keyword(s):  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Pillared Clays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dissolved Iron ◽  
Surface Areas ◽  
Accessible Surface ◽  
Adsorption Desorption ◽  
Villiger Oxidation

AbstractThree types of AlFePILCs pillared clays have been prepared from Algerian clay precursors. They have been characterized and tested in the Baeyer–Villiger oxidation of cyclohexanone to caprolactone using benzaldehyde and oxygen as oxidant at room temperature. The structural and textural properties of the catalyst have been determined by X-ray diffraction, nitrogen adsorption-desorption isotherms and Mössbauer spectroscopy.The different activities of the clays have been related to their Fe contents and accessible surface areas. The induction period observed before the reaction started has been attributed to the dissolution of a portion of the Fe3+ cations, mediated by either the perbenzoic acid intermediate or the benzoic acid co-product. The reaction was indeed catalysed by a few ppm of dissolved iron cations and the catalysis of the Baeyer–Villiger oxidation reaction should mechanistically be considered as homogeneous.

Study of Preparation, Characterization and Temperature-Programmed Reduction of NiO-ZnO Binary Materials

2013 ◽  
Vol 664 ◽  
pp. 515-520
Author(s):  
Chih Wei Tang ◽  
Jiunn Jer Hwang ◽  
Shie Hsiung Lin ◽  
Chin Chun Chung
Keyword(s):  
Weight Percent ◽  
Precipitation Method ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Temperature Programmed ◽  
Co Precipitation ◽  
Adsorption Desorption

The NiO-ZnO binary materials had been prepared by co-precipitation method. The weight percent of nickel of NiO-ZnO materials were 5, 10 and 20; they were pretreated under air at temperature of 300, 500 and 700°C, respectively. The characterization of NiO-ZnO materials were the thermal gravity analysis(TGA), X-ray diffraction(XRD), N2 adsorption-desorption at 77K, scaning electron microscope(SEM) and temperature-programmed reduction(TPR). The results revealed that surface areas of NiO-ZnO materials order from large to small were 20NiZn(OH)x(66 m2·g-1) > 10NiZn(OH)x(34 m2·g-1) > 5NiZn(OH)x(9 m2·g-1) after being calcined at the temperature of 500°C. Further, NiO-ZnO materials had two main reductive peaks at 390-415°C and 560-657°C, respectively. In all NiO-ZnO materials, 20NiZn(OH)x-C500 material had the highest surface area and the best interaction between NiO and ZnO.

scholarly journals Adsorption of Arsenate from Aqueous Solution onto Modified Vietnamese Bentonite

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Nguyen Le My Linh ◽  
Duc Hoang Van ◽  
Tran Duong ◽  
Mai Xuan Tinh ◽  
Dinh Quang Khieu
Keyword(s):  
Aqueous Solution ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Surface Areas ◽  
Layered Clays ◽  
Monolayer Adsorption ◽  
Langmuir Isotherm Model ◽  
Adsorption Desorption

In this study, pillared layered clays were prepared by modifying Vietnamese bentonite with polymeric Al and Fe. The obtained materials were characteristic of X-ray diffraction analysis, thermal analysis, and nitrogen adsorption/desorption isotherms. The results indicated that hydroxy-aluminum ([Al13O4(OH)24(H2O)12]7+) and poly-hydroxyl-Fe or polyoxo-Fe cations were intercalated into layers of clay, resulting in an increase of d001 values and of the specific surface areas compared with those of initial bentonite. Modified bentonites were employed to adsorb As(V) from aqueous solution. The adsorption of As(V) was strongly dependent on solution pH, and the maximum adsorption of modified bentonites was obtained in the pH 3.0 for Fe-bentonite and the pH 4.0 for Al-bentonite. The equilibrium adsorption study showed that the data were well fit by the Langmuir isotherm model. The maximum monolayer adsorption capacity of As(V) at 30°C derived from the Langmuir equation was 35.71 mg/g for Al-bentonite and 18.98 mg/g for Fe-bentonite. Adsorption kinetics, thermodynamics, and reusability of modified bentonites have been addressed.

scholarly journals Simple Solvothermal Approach to Highly Nanostructured Hematite Thin Films

2020 ◽  
Author(s):  
Casey M. Platnich ◽  
Jachym Slaby ◽  
David O'Connell ◽  
Simon Trudel
Keyword(s):  
Thin Films ◽  
Precursor Solution ◽  
Photoelectrochemical Cells ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Surface Areas ◽  
Nucleation Sites ◽  
Synthetic Procedure

<div>In this work, we present a solvothermal method for the synthesis of hematite thin films on fluorine-doped tin oxide</div><div>substrates. This simple method uses a precursor solution of iron(III) 2,4-pentanedionate dissolved in ethanol with a</div><div>microliter-scale amount of water and yields hematite ~ 500-nm thick films after annealing. The synthesised films</div><div>were characterised using an array of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance, and powder x-ray diffraction. Incorporating water into the precursor solution provides nucleation sites for the reaction and results show that by altering the amount of water used in the synthesis, it is possible to generate nanocrystalline films of different morphologies, nanocrystal size distributions, and surface areas. This synthetic procedure therefore provides control over the films’ physical and electrochemical characteristics. Doping of hematite thin films is also possible using this synthesis, as exemplified by doping with tin by adding tin(II) 2,4-pentanedionate to the precursor solution. To demonstrate utility, we build prototype photoelectrochemical cells using the synthesized hemtatite as the photoanode.</div>

scholarly journals Preparation of a new micro-mesoporous omega zeolite by hydrothermal route: Effect of crystallization time

2021 ◽  
Author(s):  
Nabila Bouchiba ◽  
Nadia Toumi ◽  
Abdelkader Bengueddach
Keyword(s):  
Self Assembly ◽  
Crystallization Time ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Characterization Methods ◽  
X Ray ◽  
New Applications ◽  
Adsorption Desorption ◽  
Zeolite Precursors

Abstract This work concerns the preparation of a new micro-mesoporous omega zeolite by hydrothermal route. This method consists of the self-assembly of the omega zeolite precursors with a cethyltrimethyl-ammonium bromide surfactant. Different stages of crystallization were studied in order to determine their impact on the textural and structural properties of the resulting materials. For this, several characterization methods were used such as X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy, and Energy-Dispersive X-ray. The results showed that the processing time significantly influences on the crystallinity, porosity and Si/Al ratio of the resulting materials. A specific surface area almost three times greater than the parent zeolite was obtained when using non-hydrothermally treated zeolite precursors. While the precursors prepared hydrothermally for 48 hours or 72 hours essentially lead to the formation of the microporous phase corresponding to the Omega zeolite. These new properties can open new applications of these solids notably in the catalysis for the conversion of bulky molecules and also in the adsorption of organic and organic pollutants.

scholarly journals Influence of the Presence of Different Alkali Cations and the Amount of Fe(CN)6 Vacancies on CO2 Adsorption on Copper Hexacyanoferrates

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3371 ◽  
Author(s):  
Svensson ◽  
Grins ◽  
Eklöf ◽  
Eriksson ◽  
Wardecki ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Prussian Blue ◽  
Co2 Adsorption ◽  
X Ray Diffraction ◽  
Alkali Cations ◽  
Prussian Blue Analogue ◽  
X Ray ◽  
Infra Red ◽  
Adsorption Desorption ◽  
Adsorption Capability

The CO2 adsorption on various Prussian blue analogue hexacyanoferrates was evaluated by thermogravimetric analysis. Compositions of prepared phases were verified by energy-dispersive X-ray spectroscopy, infra-red spectroscopy and powder X-ray diffraction. The influence of different alkali cations in the cubic Fm3m structures was investigated for nominal compositions A2/3Cu[Fe(CN)6]2/3 with A = vacant, Li, Na, K, Rb, Cs. The Rb and Cs compounds show the highest CO2 adsorption per unit cell, 3.3 molecules of CO2 at 20 C and 1 bar, while in terms of mmol/g the Na compound exhibits the highest adsorption capability, 3.8 mmol/g at 20 C and 1 bar. The fastest adsorption/desorption is exhibited by the A-cation free compound and the Li compound. The influence of the amount of Fe(CN)6 vacancies were assessed by determining the CO2 adsorption capabilities of Cu[Fe(CN)6]1/2 (Fm3m symmetry, nominally 50% vacancies), KCu[Fe(CN)6]3/4 (Fm3m symmetry, nominally 25% vacancies), and CsCu[Fe(CN)6] (I-4m2 symmetry, nominally 0% vacancies). Higher adsorption was, as expected, shown on compounds with higher vacancy concentrations.

Preparation of Visible-Light-Responsive TiO2-xNx Photocatalyst by a Very Simple Method

2011 ◽  
Vol 383-390 ◽  
pp. 3188-3191
Author(s):  
Han Jie Huang ◽  
Wen Long She ◽  
Ling Wen Yang ◽  
Hai Peng Huang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflection ◽  
Ammonia Solution ◽  
Reflection Spectra ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Light Excitation

A visible-light-responsive TiO2-xNx photocatalyst was prepared by a very simple method. Ammonia solution was used as nitrogen resource in this paper. The TiO2-xNx photocatalyst was characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflection spectra (DRS), and X-ray photoelectron spectroscopy (XPS). The ethylene was selected as a target pollutant under visible light excitation to evaluate the activity of this photocatalyst. The new prepared TiO2-xNx photocatalyst with strong photocatalytic activity under visible light irradiation was demonstrated in the experiment.

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