Carbon dioxide methanation over Ni-M/Al2O3 (M: Fe, CO, Zr, La and Cu) catalysts synthesized using the one-pot sol-gel synthesis method

2018 ◽  
Vol 43 (34) ◽  
pp. 16522-16533 ◽  
Author(s):  
Shima Valinejad Moghaddam ◽  
Mehran Rezaei ◽  
Fereshteh Meshkani ◽  
Reihaneh Daroughegi
2001 ◽  
Vol 79 (8) ◽  
pp. 1220-1223 ◽  
Author(s):  
Quan Zhuang ◽  
Jack M Miller

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.


2014 ◽  
Vol 2 (40) ◽  
pp. 8607-8613 ◽  
Author(s):  
Benjamin Ritter ◽  
Thoralf Krahl ◽  
Knut Rurack ◽  
Erhard Kemnitz

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


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ulises Arellano Sánchez ◽  
Lifang Chen ◽  
Jin An Wang ◽  
Luis Enrique Noreña ◽  
Maximiliano Asomoza ◽  
...  

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.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1554
Author(s):  
Justinas Januskevicius ◽  
Zivile Stankeviciute ◽  
Dalis Baltrunas ◽  
Kęstutis Mažeika ◽  
Aldona Beganskiene ◽  
...  

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.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3876
Author(s):  
Jesús Valdés ◽  
Daniel Reséndiz ◽  
Ángeles Cuán ◽  
Rufino Nava ◽  
Bertha Aguilar ◽  
...  

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.


2016 ◽  
Vol 2 (1) ◽  
pp. 23-30 ◽  
Author(s):  
O.S.N. Ghosh ◽  
◽  
S. Gayathri ◽  
D. Alagarasan ◽  
K.V.P. Kumar ◽  
...  

2018 ◽  
Vol 5 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Yu.S. Demidova ◽  
I.L. Simakova ◽  
E.V. Suslov ◽  
K.P. Volcho ◽  
N.F. Salakhutdinov ◽  
...  

Abstract In the current work gold catalysts supported on both commercial oxides and oxides synthesized by the sol-gel method were used for the one-pot alcohol amination of myrtenol. In general, utilization of metal oxides synthesized by the sol-gel method as the gold catalyst support enhanced the knowledge regarding key parameters determining catalytic behavior. Synthesized alumina was characterized by stronger acid sites favoring primary amine accumulation on the catalyst surface, as compared to the commercial oxide. Utilization of mixed metal oxides synthesized by the sol-gel method resulted in the non-additive behavior of different oxides enhancing the catalytic activity. Introduction of ceria into alumina modified the support basicity resulting in more efficient alcohol activation.


2020 ◽  
Vol 96 (1) ◽  
pp. 236-246
Author(s):  
Marta Gallo ◽  
Fabio Giudice ◽  
Mauro Banchero ◽  
Silvia Ronchetti ◽  
Luigi Manna ◽  
...  

Abstract Curcumin is a natural active principle with antioxidant, antibacterial and anti-inflammatory properties. Its use is limited by a low water solubility and fast degradation rate, which hinder its bioavailability. To overcome this problem, curcumin can be delivered through a carrier, which protects the drug molecule and enhances its pharmacological effects. The present work proposes a simple one-pot sol–gel synthesis to obtain a hybrid carrier for curcumin delivery. The hybrid consists of a mesostructured matrix of amorphous silica, which stabilizes the carrier, and hexadecyltrimethylammonium (CTA), a surfactant where curcumin is dissolved to increase its water solubility. The carrier was characterized in terms of morphology (FESEM), physicochemical properties (XRD, FTIR, UV spectroscopy) and release capability in pseudo-physiological solutions. Results show that curcumin molecules were entrapped, for the first time, in a silica-surfactant mesostructured hybrid carrier. The hybrid carrier successfully released curcumin in artificial sweat and in a phosphate buffer saline solution, so confirming its efficacy in increasing curcumin water solubility. The proposed drug release mechanism relies on the degradation of the carrier, which involves the concurrent release of silicon. This suggests strong potentialities for topical administration applications, since curcumin is effective against many dermal diseases while silicon is beneficial to the skin.


2020 ◽  
Vol 362 (14) ◽  
pp. 2961-2969 ◽  
Author(s):  
Paolo Sonzini ◽  
Caterina Damiano ◽  
Daniela Intrieri ◽  
Gabriele Manca ◽  
Emma Gallo
Keyword(s):  
One Pot ◽  

2017 ◽  
Vol 41 (13) ◽  
pp. 5893-5903 ◽  
Author(s):  
Zeba Nasir ◽  
Abad Ali ◽  
Mohammad Shakir ◽  
Rizwan Wahab ◽  
Shamsuzzaman Shamsuzzaman ◽  
...  

Heterogeneous and versatile NiO–SiO2 NCs were synthesized by a sol–gel technique and used as a catalyst for the one-pot multicomponent synthesis of benzodiazepines.


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