scholarly journals Aerobic oxidative desulfurization via magnetic mesoporous silica-supported tungsten oxide catalysts

2020 ◽  
Vol 17 (5) ◽  
pp. 1422-1431
Author(s):  
Wei Jiang ◽  
Xiang Gao ◽  
Lei Dong ◽  
Jin Xiao ◽  
Lin-Hua Zhu ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Tungsten Oxide ◽  
Molecular Oxygen ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
High Catalytic Activity ◽  
Diesel Fuels ◽  
Magnetically Separable Catalyst ◽  
Ft Ir ◽  
Magnetic Mesoporous Silica

Abstract It is usually difficult to remove dibenzothiophenes from diesel fuels by oxidation with molecular oxygen as an oxidant. In the study, tungsten oxide was supported on magnetic mesoporous silica by calcination to form a magnetically separable catalyst for oxidative desulfurization of diesel fuel. By tuning different calcining temperatures, the catalyst calcined at 500 °C showed a high catalytic activity with molecular oxygen as the oxidant. Under optimal reaction conditions, the sulfur removal of DBT reached 99.9% at 120 °C after 8 h. Furthermore, the removals of 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene could also get up to 98.2% and 92.3% under the same conditions. The reaction mechanism was explored by selective quenching experiments and FT-IR spectra.

scholarly journals Catalytic Oxidative/Extractive Desulfurization of Model Oil using Transition Metal Substituted Phosphomolybdates-Based Ionic Liquids

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 639 ◽  
Author(s):  
Yunlei Li ◽  
Yanjie Zhang ◽  
Panfeng Wu ◽  
Caiting Feng ◽  
Ganglin Xue
Keyword(s):  
Catalytic Activity ◽  
Ionic Liquids ◽  
Transition Metal ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
High Catalytic Activity ◽  
Reaction Conditions ◽  
Extraction Solvent ◽  
Model Oil ◽  
Optimal Reaction

Polyoxometalates based ionic liquids (POM-ILs) exhibit a high catalytic activity in oxidative desulfurization. In this paper, four new POM-IL hybrids based on transition metal mono-substituted Keggin-type phosphomolybdates, [Bmim]5[PMo11M(H2O)O39] (Bmim = 1-butyl 3-methyl imidazolium; M = Co2+, Ni2+, Zn2+, and Mn2+), have been synthesized and used as catalysts for the oxidation/extractive desulfurization of model oil, in which ILs are used as the extraction solvent and H2O2 as an oxidant under very mild conditions. The factors that affected the desulfurization efficiency were studied and the optimal reaction conditions were obtained. The results showed that the [Bmim]5[PMo11Co(H2O)O39] catalyst demonstrated the best catalytic activity, with sulfur-removal of 99.8%, 85%, and 63% for dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT), respectively, in the case of extraction combining with a oxidative desulfurization system under optimal reaction conditions (5 mL model oil (S content 500 ppm), n(catalyst) = 4 μmol, n(H2O2)/n(Substrate) = 5, T = 50 °C for 60 min with [Omim]BF4 (1 mL) as the extractant). The catalyst can be recycled at least 8 times, and still has stability and high catalytic activity for consecutive desulfurization. Probable reaction mechanisms have been proposed for catalytic oxidative/extractive desulfurization.

A Novel Oxidative Desulfurization System for Diesel Fuels with Molecular Oxygen in the Presence of Cobalt Catalysts and Aldehydes

2004 ◽  
Vol 18 (1) ◽  
pp. 116-121 ◽  
Author(s):  
Satoru Murata ◽  
Kazutaka Murata ◽  
Koh Kidena ◽  
Masakatsu Nomura
Keyword(s):  
Molecular Oxygen ◽  
Oxidative Desulfurization ◽  
Cobalt Catalysts ◽  
Diesel Fuels

scholarly journals Yolk–shell structured magnetic mesoporous silica: a novel and highly efficient adsorbent for removal of methylene blue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reza Mirbagheri ◽  
Dawood Elhamifar ◽  
Masoumeh Shaker
Keyword(s):  
Methylene Blue ◽  
Mesoporous Silica ◽  
High Efficiency ◽  
Nitrogen Adsorption ◽  
Organic Dye ◽  
Ft Ir ◽  
Water Pollutant ◽  
Adsorption Desorption ◽  
Efficient Adsorbent ◽  
Magnetic Mesoporous Silica

AbstractIn this study, a novel magnetic mesoporous silica with yolk–shell structure (Fe3O4@[email protected]) was successfully synthesized via a polymer-template assisted method. The Fe3O4@[email protected] was characterized by using FT-IR, EDS, SEM, TEM, VSM, PXRD and nitrogen adsorption–desorption analyses. The Fe3O4@[email protected] nanocomposite showed high efficiency in adsorption of an organic dye and water pollutant called methylene blue (MB) with 98.2% removal capability. Furthermore, the effect of different parameters in the adsorption of MB was investigated. Different models of kinetic were examined and compared with each other. The recoverability and reusability of designed Fe3O4@[email protected] material were also studied under applied conditions.

scholarly journals Fabrication of the magnetic mesoporous silica Fe-MCM-41-A as efficient adsorbent: performance, kinetics and mechanism

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yige Guo ◽  
Bin Chen ◽  
Ying Zhao ◽  
Tianxue Yang
Keyword(s):  
Mesoporous Silica ◽  
Zero Valent Iron ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Environment And Health ◽  
Transmission Electron ◽  
Order Kinetic Model ◽  
Neutral Conditions ◽  
Magnetic Mesoporous Silica ◽  
Mcm 41

AbstractAntibiotics are emerging pollutants and increasingly present in aquaculture and industrial wastewater. Due to their impact on the environment and health, their removal has recently become a significant concern. In this investigation, we synthesized nano zero-valent iron-loaded magnetic mesoporous silica (Fe-MCM-41-A) via precipitation and applied the adsorption of oxytetracycline (OTC) from an aqueous solution. The effects of competing ions such as Na+, Ca2+ and Cu2+ on the adsorption process under different pH conditions were studied in depth to providing a theoretical basis for the application of nanomaterials. The characterization of the obtained material through transmission electron microscopy demonstrates that the adsorbent possesses hexagonal channels, which facilitate mass transfer during adsorption. The loaded zero-valent iron made the magnetic, and was thus separated under an applied magnetic field. The adsorption of OTC onto Fe-MCM-41-A is rapid and obeys the pseudo-second-order kinetic model, and the maximum adsorption capacity of OTC is 625.90 mg g−1. The reaction between OTC and Fe-MCM-41-A was inner complexation and was less affected by the Na+. The effect of Ca2+ on the adsorption was small under acidic and neutral conditions. However, the promotion effect of Ca2+ increased by the increase of pH. Cu2+ decreased the removal efficiencies continuously and the inhibitory effects decrease varied with the increase of pH. We propose that surface complexing, ion-exchange, cationic π-bonding, hydrogen bonding, and hydrophobicity are responsible for the adsorption of OTC onto Fe-MCM-41-A.

Synthesis of magnetic mesoporous silica composites via a modified Stöber approach

2014 ◽  
Vol 21 (5) ◽  
pp. 513-519 ◽  
Author(s):  
Fei Wang ◽  
Ziheng Li ◽  
Dan Liŭ ◽  
Guoqiang Wang ◽  
Dan Liú
Keyword(s):  
Mesoporous Silica ◽  
Magnetic Mesoporous Silica

Efficient Oxidative Desulfurization (ODS) of Commercial Diesel with TBHP under Mild Conditions Catalyzed by Polymolybdates Supported on Al2O3

2015 ◽  
Vol 1107 ◽  
pp. 341-346
Author(s):  
Wan Nazwanie Wan Abdullah ◽  
Rusmidah Ali ◽  
Wan Azelee Wan Abu Bakar
Keyword(s):  
Sulfur Content ◽  
Research Work ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
Catalyst System ◽  
Impregnation Method ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Alternative Method ◽  
Tert Butyl Hydroperoxide

Due to the low specifications for sulfur content in diesel, a lot of research work are been conducted to develop alternative method for desulfurization. Catalytic oxidative desulfurization (Cat-ODS) has been found to be an alternative method to replace a conventional method which is hydrodesulfurization.New catalyst formulation using tert-butyl hydroperoxide polymolybdate based catalyst system was investigated in this research utilizing tert-butyl hydroperoxide (TBHP) as oxidant and dimethylformamide (DMF) as solvent for extraction. A series of polymolybdate supported alumina catalysts were prepared using wet impregnation method, ageing at ambient room temperature for 24 hours and followed by calcination process. A commercial diesel with 440 ppmw of total sulfur was employed to evaluate the elimination of sulfur compounds. Besides, the percentage of sulfur removal was measured by gas chromatography-flame photometric detector (GC-FPD). The sulfur content in commercial diesel was successfully reduced from 440 ppmw to 35 ppmw under mild condition followed by solvent extraction. From catalytic testing, Mo-Al2O3 calcined at 500°C was revealed as the most potential catalyst which gave 92% of sulfur removal.

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