One-pot sol-gel synthesis of sulfated ZrO2-SiO2 catalysts for alcohol dehydration

2001 ◽  
Vol 79 (8) ◽  
pp. 1220-1223 ◽  
Author(s):  
Quan Zhuang ◽  
Jack M Miller
Keyword(s):  
Ammonium Sulfate ◽  
Sulfated Zirconia ◽  
Sol Gel ◽  
Synthesis Method ◽  
Acid Catalyst ◽  
Alcohol Dehydration ◽  
One Pot ◽  
Zirconium Propoxide ◽  
The One ◽  
Sol Gel Synthesis

Sulfated ZrO2–SiO2 catalysts were synthesized by one-pot sol-gel method using ammonium sulfate, zirconium propoxide, and tetraethyl orthosilicate as precursors. The catalysts were characterized by N2 adsorption and DRIFTS. On calcining the gel at elevated temperature, the ammonium sulfate decomposed, giving a sulfated zirconia–silica catalyst. By adding ammonium sulfate to the sol-gel synthesis system, the surface area, pore size, and pore volume of the resultant catalyst were increased. The one-pot sol-gel synthesized catalyst with an optimum loading of SO42– 14 mol% showed significantly higher catalytic activity, with a selectivity of 100%, for isopropanol dehydration when compared to the impregnated catalyst. The one-pot sol-gel synthesis method is an effective way to prepare sulfated zirconia catalyst.Key words: sulfated zirconia, sol-gel synthesis, acid catalyst, alcohol dehydration, N2 adsorption, DRIFT.

Sol-gel synthesis of ternary phosphate-ZrO2-SiO2 catalysts for alcohol dehydration

2001 ◽  
Vol 79 (8) ◽  
pp. 1224-1228 ◽  
Author(s):  
Quan Zhuang ◽  
Jack M Miller
Keyword(s):  
Key Words ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Tetraethyl Orthosilicate ◽  
Mas Nmr ◽  
Alcohol Dehydration ◽  
Zirconium Propoxide ◽  
P Content ◽  
Sol Gel Synthesis ◽  
Cp Mas Nmr

Phosphate–ZrO2–Si2O catalysts were synthesized by sol-gel method using tributyl phosphite, zirconium propoxide, and tetraethyl orthosilicate as precursors. They were characterized by N2 adsorption, 31P CP MAS NMR, and DRIFTS. At lower P content, monomeric phosphates were formed on the surface of the catalysts, which were mainly responsible for the isopropanol dehydration activity. At higher P content, polyphosphates were formed, and thus, the dehydration activity decreased. An optimum P content for dehydration activity was found to be at 10 mol%.Key words: sol-gel synthesis, ternary oxides, phosphate, acid catalyst, alcohol dehydration, 31P CP MAS NMR, N2 adsorption, DRIFTS.

scholarly journals Nanoscale CaF2 doped with Eu3+ and Tb3+ through fluorolytic sol–gel synthesis

2014 ◽  
Vol 2 (40) ◽  
pp. 8607-8613 ◽  
Author(s):  
Benjamin Ritter ◽  
Thoralf Krahl ◽  
Knut Rurack ◽  
Erhard Kemnitz
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Synthesis Method ◽  
One Pot ◽  
One Pot Synthesis ◽  
Sol Gel Synthesis

Easy upscaleable one-pot synthesis method at room temperature for ultra small sized Eu3+- and Tb3+-doped CaF2 nanoparticles.

Nano magnetic sulfated zirconia (Fe3O4@ZrO2/SO42−): an efficient solid acid catalyst for the green synthesis of α-aminonitriles and imines

2015 ◽  
Vol 39 (6) ◽  
pp. 4821-4829 ◽  
Author(s):  
Hossein Ghafuri ◽  
Afsaneh Rashidizadeh ◽  
Behnaz Ghorbani ◽  
Majid Talebi
Keyword(s):  
Green Synthesis ◽  
Sulfated Zirconia ◽  
Solid Acid ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
One Pot ◽  
Nano Catalyst ◽  
The One

In this research, nano magnetic sulfated zirconia was prepared through a green and facile method and acted as a novel, heterogeneous, efficient nano-catalyst for the one-pot three component synthesis of α-aminonitrile derivatives.

Preparation, Characterization and Catalytic Activity of Sulfated Zirconia by Varied Sol-Gel Method

2015 ◽  
Vol 1123 ◽  
pp. 96-99
Author(s):  
Is Fatimah ◽  
Zulfa Zuhrufa
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Sulfated Zirconia ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Bet Surface Area ◽  
Ammonium Bromide ◽  
Templating Method ◽  
Prepared Material ◽  
Sol Gel Synthesis

The sulfated zirconia catalysts were was prepared by sol–gel processes consist of varied templating method. Both preparations consist of sol-gel synthesis of zirconium dioxide followed by sulfatation process by using NH4SO4solid reaction method. Two different templating agent; urea and cetyltrimetyl ammonium bromide was used in sol-gel processes. The prepared material was characterized using scanning electron microscope (SEM), x-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) measurements. From the XRD measurement it can be concluded that both materials consist of ZrO2in combined phases while from BET surface area analysis it can be noted that material prepared by urea template has higher specific surface area compared to that use CTAB template. Both materials exhibit the activity as acid catalyst in microwave assisted conversion of citronellal. It is also confirmed that the higher the surface area the higher total conversion of citronellal obtained. Study on the correlation between physicochemical properties of materials with the catalytic activity was discussed in this paper.

scholarly journals One-Pot Synthesis of W-TiO2/SiO2 Catalysts for the Photodegradation of p-Nitrophenol

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ulises Arellano Sánchez ◽  
Lifang Chen ◽  
Jin An Wang ◽  
Luis Enrique Noreña ◽  
Maximiliano Asomoza ◽  
...  
Keyword(s):  
Surface Area ◽  
Heterogeneous Catalysts ◽  
Sol Gel ◽  
Synthesis Method ◽  
Band Gap Energy ◽  
High Photocatalytic Activity ◽  
Basic Medium ◽  
One Pot ◽  
Surface Hydroxyl ◽  
The One

Double modifications of TiO2 by doping with WO3 and by dispersing on a SiO2 support were made by the one-pot sol-gel method. Doping with W shifts the TiO2 band gap energy from 3.2 eV to around 3.06 eV. The surface area of the supported W-TiO2/SiO2 material was significantly increased, by approximately 3 times, in comparison to the bare TiO2. The photocatalytic activities of the catalysts were evaluated in the degradation reaction of p-nitrophenol in aqueous solution and basic medium. After 240 min of photodegradation, more than approximately 99% p-nitrophenol could be mineralized with the most active W-TiO2/SiO2 catalyst. Under UV irradiation, p-nitrophenol was initially photodegraded into hydroquinone and benzosemiquinone intermediates, which were further degraded into smaller fragments such as organic carboxylic acids and finally completely mineralized. A proposed photoreaction mechanism was presented based on the key roles of the surface hydroxyl species and superoxide radicals such as O2- and ⋅OH, together with W6+/W5+ couples and e-/h+ pairs in the catalysts in the p-nitrophenol photodegradation. The one-pot sol-gel synthesis method was proven to be effective to obtain W-TiO2/SiO2 catalyst with large surface area and high photocatalytic activity, and it can be also used for the preparation of other heterogeneous catalysts.

scholarly journals Aqueous Sol-Gel Synthesis of Different Iron Ferrites: From 3D to 2D

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1554
Author(s):  
Justinas Januskevicius ◽  
Zivile Stankeviciute ◽  
Dalis Baltrunas ◽  
Kęstutis Mažeika ◽  
Aldona Beganskiene ◽  
...  
Keyword(s):  
Magnetic Measurements ◽  
Substrate Surface ◽  
Sol Gel ◽  
Synthesis Method ◽  
Xrd Analysis ◽  
Dip Coating ◽  
Yttrium Iron ◽  
Iron Garnet ◽  
Dip Coating Technique ◽  
Sol Gel Synthesis

In this study, an aqueous sol-gel synthesis method and subsequent dip-coating technique were applied for the preparation of yttrium iron garnet (YIG), yttrium iron perovskite (YIP), and terbium iron perovskite (TIP) bulk and thin films. The monophasic highly crystalline different iron ferrite powders have been synthesized using this simple aqueous sol-gel process displaying the suitability of the method. In the next step, the same sol-gel solution was used for the fabrication of coatings on monocrystalline silicon (100) using a dip-coating procedure. This resulted, likely due to substrate surface influence, in all coatings having mixed phases of both garnet and perovskite. Thermogravimetric (TG) analysis of the precursor gels was carried out. All the samples were investigated by X-ray powder diffraction (XRD) analysis. The coatings were also investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Mössbauer spectroscopy. Magnetic measurements were also carried out.

scholarly journals Sol-Gel Synthesis of the Double Perovskite Sr2FeMoO6 by Microwave Technique

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3876
Author(s):  
Jesús Valdés ◽  
Daniel Reséndiz ◽  
Ángeles Cuán ◽  
Rufino Nava ◽  
Bertha Aguilar ◽  
...  
Keyword(s):  
Particle Size ◽  
Hydrothermal Synthesis ◽  
Microwave Radiation ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Synthesis Method ◽  
Double Perovskite ◽  
Synthesis Methods ◽  
X Ray ◽  
Sol Gel Synthesis

The effect of microwave radiation on the hydrothermal synthesis of the double perovskite Sr2FeMoO6 has been studied based on a comparison of the particle size and structural characteristics of products from both methods. A temperature, pressure, and pH condition screening was performed, and the most representative results of these are herein presented and discussed. Radiation of microwaves in the hydrothermal synthesis method led to a decrease in crystallite size, which is an effect from the reaction temperature. The particle size ranged from 378 to 318 nm when pH was 4.5 and pressure was kept under 40 bars. According to X-ray diffraction (XRD) results coupled with the size-strain plot method, the product obtained by both synthesis methods (with and without microwave radiation) have similar crystal purity. The Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) techniques showed that the morphology and the distribution of metal ions are uniform. The Curie temperature obtained by thermogravimetric analysis indicates that, in the presence of microwaves, the value was higher with respect to traditional synthesis from 335 K to 342.5 K. Consequently, microwave radiation enhances the diffusion and nucleation process of ionic precursors during the synthesis, which promotes a uniform heating in the reaction mixture leading to a reduction in the particle size, but keeping good crystallinity of the double perovskite. Precursor phases and the final purity of the Sr2FeMoO6 powder can be controlled via hydrothermal microwave heating on the first stages of the Sol-Gel method.

ZrOCl2·8H2O: an efficient Lewis acid catalyst for the one-pot multicomponent synthesis of β-acetamido ketones

Tetrahedron ◽  
2006 ◽  
Vol 62 (17) ◽  
pp. 4059-4064 ◽  
Author(s):  
Rina Ghosh ◽  
Swarupananda Maiti ◽  
Arijit Chakraborty ◽  
Santu Chakraborty ◽  
Alok K. Mukherjee
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Lewis Acid Catalyst ◽  
The One
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