- Surfactant-encapsulated high-nuclear polyoxometalate complexes for catalytic oxidative desulfurization of model oil
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Two novel surfactant-encapsulated high-nuclear polyoxometalates catalysts (DODA)20[(HPMo6O21)4(O2CCH2CO2)6]·27H2O and (DODA)10[(HPMo6O21)2(C2O4)3]·11H2O have been prepared and characterized by TG, FT-IR,1H NMR and UV-Vis. They were used for the oxidative desulfurization of model oil containing sulfur compounds such as dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), benzothiophene (BT) with H2O2as an oxidant under mild conditions. The removal of DBT, 4,6-DMDBT and BT could reach above 98% under the optimal conditions of n(S)/n(catalyst)/n(H2O2) = 220:1:880 at 60 °C for 2.5 h, 4.5 h and 5 h respectively, which improved to be a promising catalyst in the ODS process. The oxidative reactivity of the sulfur-containing compounds decreased according to DBT > 4,6-DMDBT > BT. We investigated the main factors affecting the process including temperature, the polymeric structures of catalysts, and O/S (H2O2/DBT) molar ratio in detail. Moreover, the catalyst can be reused 5 times with high recycling efficiency.
- Wang, Tingting,Lu, Ying,Wu, Hongli,Wang, Enbo
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- Trifluoromethanesulfonic acid-based DESs as extractants and catalysts for removal of DBT from model oil
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A series of deep eutectic solvents (DESs) of ChCl/XCF3SO3H (X from 1.0 to 2.0) were synthesized by stirring a mixture of choline chloride (ChCl) and trifluoromethanesulfonic acid (CF3SO3H) at room temperature. The DESs were characterized by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (1H NMR). The oxidative desulfurization of model oil was investigated using ChCl/1.5CF3SO3H as a catalyst and extraction agent, and H2O2 as the oxidant. Some reaction parameters such as type of DES, molar ratio of CF3SO3H and ChCl in DESs, H2O2 dose, reaction temperature, DES dose and type of sulfur compound were investigated. Under the optimum conditions, the removal rate of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) can reach up to 98.65% and 96.8%, respectively. After five recycling runs, the removal rate of DBT can still reach 97.16%.
- Mao, Chunfeng,Zhao, Rongxiang,Li, Xiuping,Gao, Xiaohan
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- Hexagonal nanoplates of high-quality γ-gallium oxide: Controlled synthesis and good heterogeneous catalytic performance for thiophenes
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Hexagonal nanoplates of high-quality γ-gallium oxide (γ-Ga2O3) were successfully synthesized by using a competitive and cooperative interaction model based on multiple equilibria, including a precipitation interaction, a coordination interaction and two binding interactions. The synthetic method is straightforward and affords the desired product in very high yield. It is important to note that only a combination of the coordination interaction and binding interactions can contribute to the formation of hexagonal nanoplates by effectively suppressing the generation of gallium oxide hydroxide and directly limiting the assembly of the nanoplates into microflowers. This model is significant because it allows us to understand how the disassembly process of nanostructures is related to the synergistic mechanism of multiple interactions. Furthermore, the γ-Ga2O3 hexagonal nanoplates exhibit good heterogeneous catalytic performance for the oxidation reaction of thiophenes. A possible mechanism was proposed for the catalytic process, and this may open up a new perspective in the study of oxidative desulfurization.
- Yang, Zun,Song, Le Xin,Wang, Ya Qian,Ruan, Mao Mao,Teng, Yue,Xia, Juan,Yang, Jun,Chen, Shan Shan,Wang, Fang
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- Deep oxidative desulfurization of dibenzothiophene in simulated oil and real diesel using heteropolyanion-substituted hydrotalcite-like compounds as catalysts
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Three heteropolyanion substituted hydrotalcite-like compounds (HPA-HTLcs) including Mg9Al3(OH)24[PW12O40](MgAl-PW12), Mg9Al3(OH)24[PMo12O40] (MgAl-PMo12) and Mg12Al4(OH)32[SiW12O40] (MgAl-SiW12), were synthesized, characterized and used as catalysts for the oxidative desulfurization of simulated oil (dibenzothiophene, DBT, in n-octane). MgAl-PMo12 was identified as an effective catalyst for the oxidative removal of DBT under very mild conditions of atmospheric pressure and 60 °C in a biphasic system using hydrogen peroxide as oxidant and acetonitrile as extractant. The conversion of DBT was nearly 100%. As a result, because of the influence of the electron density and the space steric hindrance, the oxidation reactivity of the different sulfur compounds in simulated oil followed the order DBT > 4,6- dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT) > thiophene (TH). When the reaction is finished, the catalysts can be recovered from the acetonitrile phase by filtration. The recovered MgAl-PMo12 retains nearly the same catalytic activity as the fresh material. Moreover, MgAl-PMo12 was found to exhibit an ideal catalytic activity in the oxidative desulfurization of real diesel resulting in a total remaining sulfur content of 9.12 ppm(w).
- Yu, Fengli,Wang, Rui
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- Boosting Oxidative Desulfurization of Model and Real Gasoline over Phosphotungstic Acid Encapsulated in Metal–Organic Frameworks: The Window Size Matters
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It is desirable to develop new materials that can efficiently lower sulfur content in fossil fuels, such as gasoline and diesel oil. Polyoxometallic acids supported on metal–organic frameworks (MOFs) are an important class of heterogeneous catalysts for oxidative desulfurization. However, there has been no comprehensive study on the correlation between desulfurization activity and the window size of MOFs. A series of robust MOFs, which include MIL-100(Fe), UiO-66, and ZIF-8, with different window sizes were exploited as hosts to encapsulate phosphotungstic acid by the “bottle around the ship” method and utilized for the ultra-deep oxidative desulfurization (ODS) of model and real gasoline. Compared with UiO-66 and ZIF-8, which have very small window sizes, mesoporous MIL-100(Fe), which has a large window size, exhibited the best catalytic performance in the ODS of refractory sulfur compounds (benzothiophene, dibenzothiophene, and 4,6-dimethyl-dibenzothiophene) and in recycling experiments. The correlations between the desulfurization activity and the window size of the corresponding MOFs could provide insights for the design of new porous catalysts for ODS and other size-selective catalysis reactions in the future.
- Wang, Xu-Sheng,Li, Lan,Liang, Jun,Huang, Yuan-Biao,Cao, Rong
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- Highly efficient extraction and oxidative desulfurization system using Na7H2LaW10O36·32-H 2O in [bmim]BF4 at room temperature
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Highly efficient, deep desulfurization of model oil containing dibenzothiophene (DBT), benzothiophene (BT), or 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved under mild conditions by using an extraction and catalytic oxidative desulfurization system (ECODS) in which a lanthanide-containing polyoxometalate Na7H2LnW 10O36·32-H2O (LnW10; Ln=Eu, La) acts as catalyst, [bmim]BF4 (bmim=1-butyl-3-methylimidazolium) as extractant, and H2O2 as oxidant. Sulfur removal follows the order DBT>4,6-DMDBT>BT at 30-°C. DBT can be completely oxidized to the corresponding sulfone in 25 min under mild conditions, and the LaW 10/[bmim]BF4 system could be recycled for ten times with only slight decrease in activity. Thus, LaW10 in [bmim]BF4 is one of the most efficient systems for desulfurization using ionic liquids as extractant reported so far.
- Xu, Junhua,Zhao, Shen,Chen, Wei,Wang, Miao,Song, Yu-Fei
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- A new organic-inorganic hybrid based on dimeric [Mn2V22O64]10 - Polyoxoanion as catalyst for oxidation of sulfides
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A new organic-inorganic hybrid compound constructed from [Mn2V22O64]10 - units, H6[(C6H4NO2Cu(H2O)4)]2[Mn2V22O64]·28H2O 1, has been synthesized and characterized by single-crystal X-ray diffraction, IR, powder X-ray diffraction (XPRD) and TG. Compound 1 is composed of dimeric [Mn2V22O64]10 - polyoxoanions, metal-organo fragments [(C6H4NO2Cu(H2O)4)]2 + and lattice water molecules. Moreover, a three-dimensional supramolecular structure is formed in 1 by the extensive hydrogen bond interaction among the terminal oxygen atoms of [Mn2V22O64]10 - anions, the coordinated waters of Cu2 + ions and crystal water molecules. Compound 1 exhibits remarkable catalytic activity for the heterogeneous oxidation of sulfides under mild condition.
- Wang, Ting-Ting,Lu, Ying,Liu, Ding,Wang, En-Bo
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- Deep desulfurization of fuels based on an oxidation/extraction process with acidic deep eutectic solvents
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The presence of organic sulfides in fuels has become a significant contributing factor to the formation of haze weather. The desulfurization of fuels has become a frontier scientific topic demanding urgent solutions. Research shows that acidic deep eutectic solvents (DESs) can provide a new route for the deep oxidation/extraction desulfurization of fuels because of their cheap and easily obtained raw materials, higher desulfurization efficiencies, environmentally friendly properties and simple synthetic procedures. Through smart design, a series of acidic DESs with different acidities were synthesized. These acidic DESs were applied for the successful deep oxidation/extraction desulfurization of model and real fuels. Results show that the acidity of deep eutectic solvents is the main factor that determines the oxidation/extraction process. The desulfurization capability has a positive correlation with the acidity of DESs, that is, the stronger a DES's acidity, the higher the desulfurization efficiencies achieved. Under optimal conditions, the desulfurization efficiencies of DESs choline chloride/p-toluenesulfonic acid (ChCl/p-TsOH) and tetrabutylammonium chloride/p-toluenesulfonic acid (TBAC/p-TsOH) can reach up to 99.99%. For the real fuel, the desulfurization efficiency can reach up to 97.25% and 95.90%, for (ChCl/p-TsOH) and (TBAC/p-TsOH) respectively. Finally, the final product was characterized and the oxidation/extraction mechanism was also investigated and the possible desulfurization route was proposed. The above study will provide new technology for the desulfurization of fuels.
- Yin, Jingmei,Wang, Jinping,Li, Zhuo,Li, Dan,Yang, Guang,Cui, Yingna,Wang, Ailing,Li, Changping
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- Oxidative desulfurization (ODS) of organosulfur compounds catalyzed by peroxo-metallate complexes of WOx-ZrO2: Thermochemical, structural, and reactivity indexes analyses
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An experimental and theoretical study on the relationships between oxidative reactivity, thermochemical viability, and structural requirement of the activity sites in oxidative desulfurization (ODS) process has been performed. A series of aromatic sulfur compounds and peroxo-metallate complexes of WOx-ZrO2 with different structures have been studied. The models chosen for mimicking the catalyst correspond to surface densities of ~7 W nm-2. The results indicate that the ODS takes place in two consecutive stages: (i) the formation of sulfoxide and (ii) the formation of sulfone. However, a detailed analysis suggests that these stages occur in two separated steps, (a) addition and (b) elimination, involving the formation of intermediate adducts and that the elimination of sulfoxide from the site surface is the rate-determining step. The results also reveal that the thermochemical feasibility of the studied reactions depends on both: the local structure of the WOx-ZrO2 surface and on the nature of the aromatic sulfur compound. It was found that the reactions involving dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (46DMDBT) are the most favored reactions, while the reaction of thiophene (Th) is the least favored. Therefore, highly substituted dibenzothiophenes are the most readily oxidized species, which is in agreement with experimental evidence. An explanation to the different reactivity shown by sulfur compounds, during ODS processes, is provided.
- Torres-Garcia,Galano,Rodriguez-Gattorno
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- Directional self-assembly of exfoliated layered europium hydroxide nanosheets and Na9EuW10O36·32H 2O for application in desulfurization
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The directional self-assembly of exfoliated layered europium hydroxide (LEuH) nanosheets and europium-containing heteropolytungstate anions has been achieved by mixing an LEuH colloidal solution and a Na9EuW 10O36·32H2O (EuW10) solution at room temperature leading to the formation of a new inorganic/inorganic hybrid material, Eu2(OH)5(EuW10O36) 0.11·5.5H2O (LEuH-EuW10). The use of LEuH-EuW10 in extractive catalytic oxidative desulfurization (ECODS) showed that highly efficient and selective deep desulfurization can be achieved in only 15 min under mild conditions. A maximum turnover number (TON) of around 1600 has been achieved. In addition, the catalyst can be recycled and reused at least 10 times with only a slight loss of catalytic efficiency. The self-assembly of exfoliated layered europium hydroxides (LEuH) and Na 9EuW10O36·32H2O (EuW 10) led to a new inorganic/inorganic hybrid material, LEuH-Euw 10. The use of LEuH-EuW10 in extractive catalytic oxidative desulfurization showed that this catalyst is highly efficient and selective for the deep desulfurization of dibenzothiophene in the presence of H2O2 and [omim]PF6 under mild conditions. Copyright
- Wang, Xiaoting,Chen, Wei,Song, Yu-Fei
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- New enantiopure bis(thioether) and bis(sulfoxide) ligands from benzothiophene
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The C2-symmetric compound 2,3,2′,3′-tetrahydro-2, 2′-bi(benzo[b]thiophenyl) and three diastereomeric bis(oxide) derivatives can be synthesized in a few steps from benzo[b]-thiophene by oxidative homocoupling of (R)-2,3-dihydro-benzo[b]thiophene 1-oxide. This new family of enantiopure bis(thioether) and bis(sulfoxide) ligands forms stable chelating PdII complexes. The fused pentacyclic structure of the complexes imparts a rigid chiral environment around the metal centre. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Madec, David,Mingoia, Francesco,Macovei, Cristian,Maitro, Guillaume,Giambastiani, Giuliano,Poli, Giovanni
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- Preparation of metallophthalocyanine functionalized magnetic silica nanotubes and its application in ultrasound-assisted oxidative desulfurization of benzothiophene
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In this study, the preparation and catalytic application of tetra-substituted carboxyl iron phthalocyanine (FeC4Pc)-loading magnetic silica nanotubes (MSNTs) in oxidative desulfurization (ODS) of benzothiophene was investigated. The resulting materials FeC4Pc-MSNTs integrate the advantages of silica nanotubes and superparamagnetic characteristics, which exhibited excellent catalytic activity and reusability. Under the best operating condition for the catalytic oxidative desulfurization, the sulfur content in model oil was reduced from 600 ppm to 35 ppm with 94% of total sulfur. Our work herein reveals that the surface functionalized MSNTs will be a promising platform as catalyst carriers.
- Wang, Fang,Wang, Guangjian,Cui, Huijie,Sun, Wantang,Wang, Tangbo
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- A Novel Oxidation of Thiophenes using HOF*MeCN
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The complex, HOF*MeCN made directly by bubbling fluorine through aqueous MeCN, oxidizes various types of thiophenes to the corresponding S,S-dioxides, including ones which could not be oxidized by any other method.
- Rozen, Shlomo,Bareket, Yifat
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- An efficient heterogeneous catalyst based on highly dispersed Na 7H2LaW10O36·32H2O nanoparticles on mesoporous silica for deep desulfurization
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A lanthanide-containing polyoxometalate of Na7H 2LaW10O36·32H2O (LaW 10) have been chemically anchored to the amino-modified mesoporous silica through an organic linker. The catalysts have been characterized by ICP-ES, FT-IR, N2 sorption measurements, UV-vis, MAS-NMR, and HR-TEM. It is found that the LaW10 nanoparticles are highly dispersed on mesoporous silica, and the resulting catalysts show highly efficient deep desulfurization in only 35 min with almost 100% conversion of dibenzothiophene by using (SiO2/NH3+/LaW10)/[bmim] BF4 (bmim = 1-butyl-3-methylimidazolium) in the presence of H 2O2 as oxidant. Furthermore, deep desulfurization proceeds smoothly in model oil with S content as low as 100 ppm. A scaled-up experiment, in which the volume of model oil increases from 5 to 1000 mL with S content of 1000 ppm, indicates that almost 100% sulfur removal can be achieved in 45 min. Additionally, the catalyst could be recycled and reused at least ten times without any decrease of the catalytic efficiency. To the best of our knowledge, the (SiO2/NH3+/LaW10)/[bmim]BF 4 catalyst system with H2O2 as oxidant exhibits great potential for practical application as desulfurization systems reported so far.
- Chen, Yang,Zhao, Shen,Song, Yu-Fei
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- Catalytic [2 + 2 + 2] cycloaddition of benzothiophene dioxides with α,ω-diynes for the synthesis of condensed polycyclic compounds
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A Rh-catalyzed intermolecular [2 + 2 + 2] cycloaddition of the 2,3-double bond of benzothiophene dioxides with α,ω-diynes gave sulfone-containing cycloadducts in high yields. This is the first example of a catalytic [2 + 2 + 2] cycloaddition that uses the
- Tahara, Yu-Ki,Gake, Manami,Matsubara, Riku,Shibata, Takanori
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- Catalytic Emulsion Based on Janus Nanosheets for Ultra-Deep Desulfurization
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Catalytic Janus nanosheets were synthesized by using an anion-exchange reaction between heteropolyacids (HPAs) and the modified ionic-liquid (IL) moieties of Janus nanosheets. Their morphology and surface properties were characterized by using SEM, energy-dispersive spectroscopy (EDS), FTIR spectroscopy, and X-ray photoelectron spectroscopy (XPS) studies. Because of their inherent Janus structure, the nanosheets exhibited good amphipathic character with ILs and oil to form a stable ILs-in-oil emulsion. Therefore, these Janus nanosheets can be used as both emulsifiers and catalysts to perform emulsive desulfurization. During this process, sulfur-containing compounds at the interface could be easily oxidized and efficiently removed from a model oil. Application of this Janus emulsion brings an efficient, useful, and green procedure to the desulfurization process. Compared with the desulfurization catalyzed by using HPAs in a conventional two-phase system, the sulfur removal of dibenzothiophene (DBT) achieved in a Janus emulsion system was improved from 68 to 97 % within 1.5 h. Moreover, this emulsion system could be demulsified easily by simple centrifugation to recover both the nanosheets and the ILs. Owing to the good structural stability of the Janus nanosheets, the sulfur removal efficiency of DBT could still reach 99.9 % after the catalytic nanosheets had been recycled at least six times.
- Xia, Lixin,Zhang, Hairan,Wei, Zhichao,Jiang, Yi,Zhang, Ling,Zhao, Jie,Zhang, Junhui,Dong, Li,Li, Erni,Ruhlmann, Laurent,Zhang, Qian
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- Sulfur elimination by oxidative desulfurization with titanium-modified SBA-16
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TiO2-modified mesoporous SBA-16 and titanium-substituted mesoporous SBA-16 were developed and tested in the oxidative desulfurization (ODS) of dibenzothiophene prevailing in liquid fuel. Pure TiO2 was used as reference. The titania-based catalysts were characterized by chemical analysis, XRD, EDX and TEM. The titanium state as tetrahedral (in Ti-SBA-16 sample) or octahedral (in TiO2/SBA-16 sample) coordination surrounding in the silicate matrix was determined by XPS, UV-vis DRS, FTIR, Raman and XANES. We assessed the impact exerted on performance of different reaction variables, including (nature and amount of the active catalytic species, phase system, molar ratio of oxidant H2O2 and DBT, reaction temperature, nature of the substrate and reuse of catalysts). In addition, we carried out a kinetic study and the activation energy was determined. We achieved 90% of S removal from a 0.2 wt.% dibenzothiophene solution at 60 °C in less than 1 h of reaction. The best catalytic results are obtained with high exposed surface of nanometric TiO2 species of TiO2/SBA-16 sample. The activated catalyst is very active in ODS reaction and can be reused four times with no loss in activity.
- Rivoira, Lorena P.,Vallés, Verónica A.,Ledesma, Brenda C.,Ponte, María V.,Martínez, María L.,Anunziata, Oscar A.,Beltramone, Andrea R.
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- Ultra-deep oxidative desulfurization of fuel with H2O2 catalyzed by phosphomolybdic acid supported on silica
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A highly active catalyst of phosphomolybdic acid (HPMo) was prepared and applied in the catalytic oxidative desulfurization (CODS) system. The catalyst was characterized by FT-IR, XRD, XPS and superconducting NMR. The influences of m(catalyst)/m(oil), V(H2O2)/V(oil), reaction temperature and reaction time on the fractional conversion of benzothiophene (BT) and dibenzothiophene (DBT) were investigated. GC-MS and micro-coulometric methods were employed to investigate the reaction. The catalyst has high desulfurization activity in the removal of BT and DBT under mild conditions. The recycling experiments indicated that DBT and BT removal could still reach 95.2% and 95.7% after 10 cycles.
- Tian, Yongsheng,Wang, Guanghui,Long, Juan,Cui, Jiawei,Jin, Wei,Zeng, Danlin
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- 12-tungstophosphoric acid/silica catalyst for oxidation of benzothiophene
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12-Tungstophosphoric acid H3[α-PW12O40] was impregnated with silica to form 12-tungstophosphoric acid/silica catalyst. Structural properties of catalyst were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and nitrogen adsorption desorption. The results showed that silica was impregnated into H3[α-PW12O40] with increasing surface area properties. The catalytic activity under mild condition from H3[α-PW12O40] after impregnation with silica slightly increased compared to original catalyst. The structure of catalyst after reaction was stable, which indicate the possibility of reusing the catalyst.
- Lesbani, Aldes,Marpaung, Arianti,Fithri, Najma Annuria,Mohadi, Risfidian
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- Aerobic oxidative desulfurization coupling of Co polyanion catalysts and: P -TsOH-based deep eutectic solvents through a biomimetic approach
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A unique coupled redox biomimetic catalytic system using the Anderson-type polyoxometallate (POM) (NH4)3Co(OH)6Mo6O18 and p-toluenesulfonic acid (p-TsOH)-based deep eutectic solvents (DESs) as cocatalysts, which served as electron donors and electron-transfer mediators (ETMs), can selectively oxidize the sulfides in diesel into their corresponding sulfones. The use of coupled redox systems with ETMs facilitates the reaction process by transporting electrons from Co-POM to the oxidant along a low-energy pathway, making DBT prone to oxidize to DBTO2. The biomimetic system demonstrates outstanding desulfurization performance with oxygen as an oxidant in the absence of sacrificial agents and under mild conditions.
- Sun, Lulu,Su, Ting,Xu, Jiajia,Hao, Dongmei,Liao, Weiping,Zhao, Yuchao,Ren, Wanzhong,Deng, Changliang,Lü, Hongying
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- Preparation of CoWO4/g-C3N4 and its Ultra-Deep Desulfurization Property
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The ultra-deep desulfurization of fuel oil has become inevitable for environmental protection. Here, CoWO4/g-C3N4 was used as a catalyst, H2O2 as an oxidant, and 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4], IL) as an extractant for the oxidative desulfurization of model oil. Scanning electron microscopy, FT-IR spectroscopy, N2 adsorption isotherms, and X-ray diffraction were used to confirm the morphology, structure, and properties of the catalysts. The influence of calcination temperature, loading dose of cobalt, amount of H2O2, reaction temperature, and other parameters were investigated. The removal rate of sulfide in model oil could reach 92.9% at 80°C in 180min under the optimal operation conditions (V(oil)≤5mL, T≤80°C, m(catalyst)≤0.03g, V(H2O2)≤0.4mL, t≤180min, V(IL)≤1.0mL). In addition, the catalyst was reused five times with no significant reduction in the catalytic activity.
- Xing, Pengfei,Zhao, Rongxiang,Li, Xiuping,Gao, Xiaohan
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- The oxidation of benzothiophene using the Keggin-type lacunary polytungstophosphate as catalysts in emulsion
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A series of emulsion catalysts were successfully synthesized with quarternary ammonium cations and heteropolyanions, and they were characterized by TG/DTA, FTIR, 31P MAS NMR and EPR. The emulsion catalyst with intact Keggin-structure, [C18H37N(CH3) 3]H2[PW12O40] (PW12), is inactive for benzothiophene (BT) oxidation with H2O2 as oxidant under atmospheric pressure at 30 °C. Moreover, the metal-substituted catalysts PW11M (M = Ti, Mn, Fe, Co, Ni and Cu) show rather low activity with the conversion less than 15% for BT oxidation. Whereas, the catalyst with mono-lacunary Keggin-structures, [C18H 37N(CH3)3]5Na2[PW 11O39] (PW11), could completely catalytic oxidize BT into the corresponding sulfone under the same conditions. After careful characterizations of the catalysts, it is found that only PW 11 catalyst could effectively transform into the active polyperoxometalates species in the presence of hydrogen peroxide in non-polar solvent.
- Zhang, Yongna,Lü, Hongying,Wang, Lu,Zhang, Yuliang,Liu, Peng,Han, Hongxian,Jiang, Zongxuan,Li, Can
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- Oxidative desulfurization of thiophene derivatives with H2O2 in the presence of catalysts based on MoO3/Al2O3 under mild conditions
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The catalysts based on MoO3/Al2O3 were synthesized and tested using aqueous hydrogen peroxide as the oxidant in the oxidative desulfurization of thiophene, benzothiophene (BT) and dibenzothiophene (DBT) into the corresponding sulfones. Among catalysts tested, 15%(MoO3–WO3)/Al2O3 prepared by a conventional impregnation method was considerably active for the oxidation of thiophene, BT and DBT, which could achieve higher than 99.2% conversions at lower reaction temperature (≤338 K). The use of hexadecyltrimethyl ammonium bromide as the phase-transfer reagent in small amounts could promote the reaction efficiently.
- Shen,Lu,Ma,He,Zhang,Zhan,Xia
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- Superhydrophobic polyoxometalate/calixarene inorganic-organic hybrid materials with highly efficient desulfurization ability
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In this paper, imidazole-based ionic liquids with different alkyl chains were covalently grafted onto calix[4]arene, which resulted in the formation of 4-6 with the molecular formula [C44H56O 4·2C4H6N2(CH 2)n]·2Br [n = 5 (4), n = 8 (5), n = 12 (6)]. Ion exchange of 4-6 with Na9EuW10O36· 32H2O (denoted EuW10) led to the formation of new inorganic-organic hybrid materials 7-9 with a molecular composition of [C 44H56O4·2C4H 6N2(CH2)n] 4.5·EuW10O36·xH2O [n = 5, x = 10 (7); n = 8, x = 7 (8); n = 12, x = 20 (9)]. Contact angles above 139° suggested superhydrophobicity of the resulting hybrid materials 7-9. Sulfur removal of dibenzothiophene by applying hybrid materials 7-9 as heterogeneous catalytic systems indicated that deep desulfurization could be achieved at 70°C in 7, 5.5, and 5 min, respectively. Hybrid materials 7-9 were demonstrated to be highly efficient and selective desulfurization systems that could be reused more than 10 times without a clear decrease in reactivity. Ion-exchange of compounds with the formula [C44H56O 4·2C4H6N2(CH 2)n]·2Br by Na9EuW10O 36·32H2O results in the formation of inorganic-organic hybrid materials, which exhibit superhydrophobicity with a contact angle of >139°. The application of these hybrids in extractive catalytic oxidative desulfurization indicates that they are highly efficient and selective heterogeneous catalytic systems. Copyright
- Zhou, Xu-Miao,Chen, Wei,Song, Yu-Fei
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- Gemini surfactants and polyoxometalates hybrid assemblies: Spacer controlled oxidative desulfurization activity
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Highly efficient, deep desulfurization of model oil containing benzothiophene, dibenzothiophene, or 4,6-dimethyldibenzothiophene has been achieved under mild conditions through the use of gemini surfactant-encapsulated H3AsMo12O40 complexes (SEPGn: n = 2, 4, 6, 8, 10) as catalysts and H2O2 as an oxidant. The unique structure of gemini surfactant provides a delicate chemical environment to facilitate the formation of active peroxo-polyoxometalates species and the penetration of apolar sulfides. The rationally designed amphiphilic structures exhibit enhanced catalytic efficiency in the oxidation of sulfides compared to conventional surfactant-encapsulated POMs utilizing single positively charged surfactants with one or two tails because of the optimal interfacial pathway for both sulfides and H2O2. Dibenzothiophene can be completely oxidized to its corresponding sulfone in 25 min under mild conditions. SEPG2 catalyst could be recycled ten times without obvious loss of activity due to its enhanced stability. Therefore, present work paves a new way to design the amphiphilic polyoxometalates via the introduction of unique surfactants through the molecular design concept.
- Ma, Zhuo,Jin, Beibei,Qiu, Yunfeng
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- Preparation and characterization of organotin-oxomolybdate coordination polymers and their use in sulfoxidation catalysis
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The organotin-oxomolybdates [(R3Sn)2MoO4]·n H2O (R = methyl, n-butyl, cyclohexyl, phenyl, benzyl) have been prepared and tested as catalysts for the oxidation of benzothiophene with aqueous hydrogen peroxide, at 35°C and atmospheric pressure. In all cases, the 1,1-dioxide was the only observed product. The kinetic profiles depend on the nature of the tin-bound R group and also on the addition of a cosolvent. For the tribenzyltin derivative, the apparent activation energies for sulfoxidation as a function of the cosolvent are in the order 1,2-dichloroethane (5 kcalmol-1) -1). The solid could be recovered by centrifugation from the three-phase (solid-liquid-liquid) system containing 1,2-dichloroethane. The catalyst was reused in a second reaction cycle with no significant loss of activity. Increasing the oxidant/substrate ratio from 2:1 to 6:1 allows the corresponding sulfone to be obtained in quantitative yield within 24 h. Changing the nature of the tin-bound R group in the catalyst precursors modifies their physical properties and hence their catalytic performance. The variation in hydrophobic/hydrophilic character is important, since the Me, nBu and Cy derivatives crystallize as anhydrous compounds, whereas the other two derivatives are hydrates. The polymers also have different structures, as evidenced by X-ray powder diffraction. Mo K-edge and Sn K-edge EXAFS spectroscopy confirmed that the structures arise from the self-assembly of tetrahedral [MoO4]2- subunits and [R3Sn]+ spacers. The Mo ... Sn separation in the trimethyltin derivative is a uniform 3.84 A. By contrast, the EXAFS results revealed the coexistence of short (3.67 - 3.79 A) and long (3.93 - 4.07 A) Mo ... Sn separations in the other coordination polymers. The catalyst precursors were also characterized in the solid state by thermogravimetric analysis, FTIR, and Raman spectroscopy, and MAS NMR (13C, 119Sn) spectroscopy.
- Abrantes, Marta,Valente, Anabela A.,Pillinger, Martyn,Goncalves, Isabel S.,Rocha, Joao,Romao, Carlos C.
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- Mechanism and optimization for oxidative desulfurization of fuels catalyzed by Fenton-like catalysts in hydrophobic ionic liquid
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Various Fenton-like catalysts prepared by choline chloride (ChCl) and metal salts (FeCl3, ZnCl2, SnCl2) were characterized by FT-IR, UV-vis, Raman, ESI-MS and elemental analysis. High desulfurization efficiency of dibenzothiophene (DBT) could be obtained not only in hydrophilic ionic liquid (IL) [Bmim]BF4 (94.9%) but also in hydrophobic IL [Omim]BF4 (97.2%) by using ChFeCl4 as a catalyst under mild conditions. ESR measurements could give the evidence that the active oxygen species generated by ChFeCl4 and H2O2 in IL were involved in the catalytic oxidation of DBT. The influential factors, including reaction time, temperature, catalyst dosage, and O/S (H 2O2/DBT) molar ratio, were investigated in detail to estimate the optimal conditions for the desulfurization system in [Omim]BF 4. The aromatic sulfur compounds, DBT, benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT), could be oxidized to the corresponding sulfones, which were detected by GC-MS. Moreover, the catalytic system containing IL and catalyst could be easily separated from oil and could be recycled at least five times without a significant decrease on removal of DBT.
- Jiang, Wei,Zhu, Wenshuai,Li, Huaming,Chao, Yanhong,Xun, Suhang,Chang, Yonghui,Liu, Hui,Zhao, Zhen
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- Oxidative Removal of Organo-sulfur Species via H2O2 Oxidation Catalyzed by Lacunary Keggin 11-tungstophosphates
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Abstract: The lacunary Keggin 11-tungstophosphates were evaluated as catalysts for the oxidation of dibenzothiophene with hydrogen peroxide as oxidant in normal octane/acetonitrile biphasic system. The Na5[PW11O39Ni] exhibited good catalytic activity with the desulfurization efficiency above 99.5%. The key factors affecting the reaction, including amount of catalyst, O/S molar ratio, catalyst dosage and initial sulfur content, were investigated, whereby the favorable conditions were determined. The presence and the oxidative effect of the peroxo-heteropoly species in the oxidative reaction were determined in the contrast experiments. Moreover, the Na5[PW11O39Ni] catalyst was confirmed to have a high potential for deep desulfurization of diesel oil.
- Wang, Han,Wang, Rui,Zhang, Yongqiang,Dou, Shuaiyong,Olga, Silchenkova,Vladimir, Korchak
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- Aerobic oxidative desulfurization of benzothiophene, dibenzothiophene and 4,6-dimethyldibenzothiophene using an Anderson-type catalyst [(C 18H37)2N(CH3)2] 5[IMo6O24]
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Benzothiophene (BT), dibenzothiophene (DBT) and 4,6- dimethyldibenzothiophene (4,6-DMDBT) are oxidized to their corresponding sulfones by an Anderson-type catalyst [(C18H37) 2N(CH3)2]5IMo6O 24 using molecular oxygen as the oxidant under mild reaction conditions. These refractory sulfur-containing compounds can be oxidized completely in the absence of any sacrificial agent. Solvents such as acetonitrile and water play a negative effect on the oxidative desulfurization system. The catalytic activities of the amphiphilic Anderson catalysts depend on the quaternary ammonium cations. The reactivity of the sulfur-containing compounds follows the order 4,6-DMDBT > DBT > BT. The Royal Society of Chemistry 2010.
- Lue, Hongying,Zhang, Yongna,Jiang, Zongxuan,Li, Can
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- Ultra-deep oxidative desulfurization of fuel with H2O2 catalyzed by molybdenum oxide supported on alumina modified by Ca2+
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A highly active catalyst of molybdenum oxide supported on mesoporous alumina modified by Ca2+ was synthesized by an in situ method and applied in the catalytic oxidative desulfurization (CODS) system. This catalyst was characterized by FT-IR, XRD, BET and XPS. The influences of m(catalyst)/m(model oil), V(H2O2)/V(model oil), reaction temperature and reaction time on oxidative desulfurization of 4,6-dimethyldibenzothiophene (4,6-DMDBT), dibenzothiophene (DBT) and benzothiophene (BT) were investigated. This catalyst has high desulfurization activity in the removal of organic sulfides under mild conditions. The catalytic oxidation reactivity of sulfur-containing compounds is in the order of DBT > 4,6-DMDBT > BT. The kinetic studies reveal that the oxidative desulfurization of the organic sulfides can present a pseudo first-order kinetic process, and the apparent activation energies of 4,6-DMDBT, DBT and BT are 34.67 kJ mol-1, 33.01 kJ mol-1 and 40.16 kJ mol-1, respectively. The recycling experiments indicate that 4,6-DMDBT, DBT and BT removal can still reach 90.0%, 89.9% and 87.3% after eight cycles.
- Jin, Wei,Tian, Yongsheng,Wang, Guanghui,Zeng, Danlin,Xu, Qian,Cui, Jiawei
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- Niobium(V) oxido tris-carbamate as easily available and robust catalytic precursor for the selective sulfide to sulfone oxidation
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The oxidation of the sulfide function promoted by a variety of vanadium compounds has been largely explored, whereas the use of homogeneous catalytic systems based on the heavier group 5 metals remains less explored. We report the use of easily available niobium and tantalum carbamates, i.e. [M(O2CNMe2)5] (M = Nb, 1; M = Ta, 2), [Nb(O2CNMe2)4], 3, [NbO(O2CNEt2)3], 4, and [NbCl3(O2CNEt2)2], 5, as effective catalysts for the conversion of a series of alkyl aryl and aromatic sulfides into the corresponding sulfones. NMR investigations on the performant niobium catalyst 4 unexpectedly revealed the substantial stability of this compound in the protic catalytic environment, and a plausible catalytic cycle was obtained by DFT studies. The two active catalytic species, i.e. 4 and its minor mono-methoxide derivative, presumably interconvert to each other exploiting the versatile coordination of the carbamato ligand.
- Bresciani, Giulio,Ciancaleoni, Gianluca,Crucianelli, Marcello,Gemmiti, Mario,Marchetti, Fabio,Pampaloni, Guido
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- Polyoxometalate-Based Organic-Inorganic Hybrids as Heterogeneous Catalysts for Cycloaddition of CO2with Epoxides and Oxidative Desulfurization Reactions
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Self-assembly of polyoxometalates, transition metal salts, and 2,6-bis(2′-pyridyl)-4-hydroxypyridine (LOH) obtained four organic-inorganic hybrids [Co2.5(LOH)(LO)2(H2O)2(PW12O39)]·3CH3CN·2OH (1), [Zn1.5(LOH)3]·(PMo12O40)·CH3OH·2H2O (2), [Cd1.5(LOH)3]·(PW12O40)·2CH3OH·1.5H2O (3), and [Mn(LOH)2]·(PW12O40)·2CH3CN·H3O (4). Hybrid 1 exhibits an extended chain, which could be further connected into a 3D supramolecular architecture by H-bonds. Hybrids 2-4 feature monomolecular structures, which are further bridged via H-bonds to yield charming 3D supramolecular structures. Noteworthy, 1 and 2 can be employed as recyclable and highly efficient heterogeneous catalysts. The activated 1 displays a high catalytic activity for the cycloaddition reaction of CO2 and epoxides. Hybrid 2 exhibits an excellent catalytic performance for the oxidative desulfurization reaction.
- Zhao, Yu-Qing,Liu, Ying-Ying,Ma, Jian-Fang
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p. 1019 - 1027
(2021/01/13)
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- Self-Assembled Polyoxometalate-Based Metal-Organic Polyhedra as an Effective Heterogeneous Catalyst for Oxidation of Sulfide
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Two polyoxovanadate-based metal-organic polyhedra with octahedral (oct) and rhombic dodecahedral (rdo) geometries have been constructed from a concave molecular building block and linear and triangular carboxylate ligands. VMOP-7 is constructed from {V5O9Cl} SBU and a linear anthracene-9,10-dicarboxylic acid ligand in which all the anthracene groups are perpendicular to the edge of the octahedron. Such an arrangement mode can effectively reduce the steric hindrance between ligands. VMOP-8 is constructed from {V5O9Cl} SBU and a triangular biphenyl 3,4,5-tricarboxylate ligand, which exhibits an elongated rhombic dodecahedral configuration due to the geometry of the ligand. Furthermore, VMOP-8 can serve as a heterogeneous catalyst and exhibits efficient and common catalytic activity for oxidative desulfurization.
- Gan, Hong-Mei,Qin, Chao,Zhao, Liang,Sun, Chunyi,Wang, Xing-Long,Su, Zhong-Min
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p. 1028 - 1034
(2021/01/26)
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- Assembly of polyoxometalate-thiacalix[4]arene-based inorganic-organic hybrids as efficient catalytic oxidation desulfurization catalysts
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Self-assembly of polyoxometalates, Ni(ii)/Ag(i) cations and tetra-[5-(mercapto)-1-methyltetrazole]-thiacalix[4]arene (L) yielded three inorganic-organic hybrids, namely, [Ni3L2(CH3OH)6(H2O)4][PMo12O40]2·3CH3OH·2H2O (1), [Ni3L2(CH3OH)6(H2O)4][PW12O40]2·3CH3OH·2H2O (2) and [Ag3L(PMo12O40)] (3). In hybrids (1) and (2), Ni(ii) cations are linked by L ligands to produce layered frameworks, and H bonds among the [PMo12O40]3?/[PW12O40]3?anions and L ligands lengthen the structures to form 3D supramolecular architectures. Hybrid (3) exhibits a 3D architecture, of which Ag(i) cations not only coordinated with the N and O atoms of L ligands and [PMo12O40]3?anions simultaneously, but also connected each other by Ag-Ag interactions. It is worth mentioning that1and3as recyclable catalysts show excellent heterogeneous catalytic activity in oxidation desulfurization reactions.
- Li, Jie,Du, Peng,Liu, Ying-Ying,Ma, Jian-Fang
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supporting information
p. 1349 - 1356
(2021/02/09)
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- A μ-AsO4-Bridging Hexadecanuclear Ni-Substituted Polyoxotungstate
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A novel tetrahedral μ-AsO4-bridging hexadecanuclear Ni-substituted silicotungstate (ST) Na21H10[(AsO4){Ni8(OH)6(H2O)2(CO3)2(A-α-SiW9O34)2}2]·60H2O (1) was made by the reactions of trivacant [A-α-SiW9O34]10- ({SiW9}) units with Ni2+ cations and Na3AsO4·12H2O and characterized by IR spectrometry, elemental analysis, thermogravimetric analysis (TGA), and powder X-ray diffraction (PXRD). 1 contains a novel polyoxoanion [(AsO4){Ni8(OH)6(H2O)2(CO3)2(A-α-SiW9O34)2}2]31- built by four trivacant Keggin [A-α-SiW9O34]10- fragments linked through an unprecedented [(AsO4){Ni8(OH)6(H2O)2(CO3)2}2]9+ cluster, where the tetrahedral AsO4 acts as an exclusively μ2-bridging unit to link multiple Ni centers; such a connection mode appears for the first time in polyoxometalate chemistry. Furthermore, the electrochemical and catalytic oxidation properties of compound 1 have been investigated.
- Lian, Chen,Li, Hai-Lou,Yang, Guo-Yu
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p. 3996 - 4003
(2021/04/07)
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- Heterogeneous catalysis with an organic-inorganic hybrid based on MoO3chains decorated with 2,2′-biimidazole ligands
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The discovery of selective heterogeneous catalytic systems for industrial oxidation processes remains a challenge. Molybdenum oxide-based polymeric hybrid materials have been shown to be oxidation catalysts under mild reaction conditions, although difficulties remain with catalyst recovery/reuse since most perform as homogeneous catalysts or possess low activity. The present study shows that the hybrid material [MoO3(2,2′-biimidazole)]·H2O (1) is a superior catalyst regarding these issues. The structure of1was confirmed (by single crystal and synchrotron X-ray powder diffraction) to comprise one-dimensional chains of corner-sharing {MoO4N2} octahedra. Strong MoO?H-N hydrogen bonds separate adjacent chains to afford parallel channels that are occupied by disordered water molecules. Hybrid1was additionally characterised by FT-IR spectroscopy,1H and13C MAS NMR, scanning electron microscopy and thermogravimetric analysis. The catalytic studies highlighted the versatility of1for oxidation reactions withtert-butylhydroperoxide as oxidant. By complementing with characterisation studies, it was verified that the reaction occurs in the heterogeneous phase, the catalyst has good stability and is recoverableviasimple procedures. The chemical reaction scope covered epoxidation and sulfoxidation, and the substrate scope included biomass-deriveddl-limonene and fatty acid methyl esters to give renewable bio-products, as well as thiophene and thioanisole substrates.
- Amarante, Tatiana R.,Neves, Patrícia,Almeida Paz, Filipe A.,Gomes, Ana C.,Pillinger, Martyn,Valente, Anabela A.,Gon?alves, Isabel S.
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p. 2214 - 2228
(2021/04/12)
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- In Situ Generated Organic Peroxides in Oxidative Desulfurization of Naphtha Reformate
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Abstract: The paper describes a method developed for the oxidation of organosulfur compounds using organic peroxides generated in situ under the action of atmospheric oxygen on gasoline fraction after reforming. Naphtha reformate that contained dibenzothiophene as a model substrate was subjected to oxidative desulfurization by organic peroxides generated in situ under atmospheric oxygen. The study examined various catalytic systems, including immobilized Anderson-type polyoxometalates, and initiators, which, in combination, provided effective generation of alkyl hydroperoxides, selective oxidation of organosulfur compounds in the hydrocarbon feedstock, and a high conversion rate.
- Akopyan, A. V.,Anisimov, A. V.,Eseva, E. A.,Sinikova, N. A.
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p. 472 - 482
(2021/06/01)
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- Synthesis and non-parametric evaluation studies on high performance of catalytic oxidation-extraction desulfurization of gasoline using the novel TBAPW11Zn?TiO2?PAni nanocomposite
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In this work, the new catalyst (assigned as TBAPW11Zn?TiO2?PAni) was successfully designed and synthesized on the basis of quaternary ammonium salt of zinc monosubstituted phosphotungstate [(n-C4H9)4N][PW11ZnO39] (TBAPW11Zn), titanium dioxide (TiO2), and polyaniline (PAni). This study reports the catalytic oxidation-extraction desulfurization (ECODS) of sulfur-containing molecules from real and the simulated (Th, BT, and DBT) gasoline using new organic–inorganic hybrid catalyst (TBAPW11Zn?TiO2?PAni). The ECODS results were shown that the concentration of sulfur compounds (SCs) of real gasoline was lowered from 0.4992 to 0.0122 wt.% with 97% efficiency at 35 °C after 1 h. Furthermore, the synthesized heterogeneous nanocatalyst showed high stability and reusability after five times without significant loss of activity. The high performance of TBAPW11Zn?TiO2?PAni/H2O2/CH3CO2H system can be a promising route with a superb potential in the generation of ultra-low-sulfur gasoline. Also the Mann–Whitney U-test results show that there is not a significant difference between the mean of sulfur percentage for DBT & BT, BT & Th and DBT & Th in the presence of the catalyst. Based on the Kruskal–Wallis test results, we can conclude that the temperature, time and amount of catalyst have a significant effect on ECODS efficiency of TBAPW11Zn?TiO2?PAni nanocomposite.
- Khanmohammadi Khorrami, Mohammad Reza,Shokri Aghbolagh, Zahra
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- Two polyoxometalate-based inorganic-organic hybrids and one coordination polymer assembled with a functionalized calix[4]arene: Catalytic and electrochemical properties
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Self-assembly of 4-pyridyl-functionalized calix[4]arene ligand 5,11,17,23-tetrakis(1,1-dimethylethyl)-25,26,27,28-tetrakis[(4-pyridylmethyl)oxy]calix[4]arene (L), Ag(I)/Cd(II) cations and polyoxometalate obtained two inorganic-organic hybrids [Ag3(L)2][PMo12O40]·CH3CN·4H2O (1), [Ag3(L)2][PMo12O40]·2DMA·0.5EtOH (2) and one complex [Cd3(L)2Cl6]·4CH3CN·4H2O (3) (DMA = N,N-dimethylacetamide). Hybrids 1 and 2 have fascinating one-dimensional chains, which are linked by hydrogen bonds between the C atoms of L ligands and the O atoms of [PMo12O40]3? anions to generate supramolecular layers. 3 displays a thick layer containing trinuclear Cd(II) clusters. Noteworthy, hybrid 1 exhibits excellent heterogeneous catalytic activity for oxidative desulfurization reaction and obvious electrocatalytic activity for oxidize ascorbic acid and reduce NaBrO3. Complex 3 shows heterogeneous catalytic ability for Knoevenagel condensation reaction.
- Li, Zhuo,Liu, Ying-Ying,Xu, Guo-Hai,Ma, Jian-Fang
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- Synergistic effects of MOF-76 on layered double hydroxides with superior activity for extractive catalytic oxidative desulfurization
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The combination of metal-organic frameworks (MOFs) with layered double hydroxides (LDHs) has been greatly limited by the agglomeration of pure MOFs and the height of the LDH gallery, so there are few reports on the combination of MOFs and LDHs. In this work, for the first time, the combination of MOF-76 with a layered double hydroxide (MOF-76?LDH) was used for desulfurization under room temperature and pressure conditions without the necessity of protecting with nitrogen. The structure of the heterogeneous catalyst was characterized using FT-IR, XRD, TG, BET, SEM, EDX, XPS, fluorescence and ICP-AES. The as-prepared catalyst exhibited superior activity in deep desulfurization of DBT (dibenzothiophene), BT (benzothiophene) and 4,6-DMDBT (4,6-dimethyldibenzothiophene). The above sulfides could be completely converted into their corresponding sulfones and sulfoxides at 60 °C in 25, 40 and 55 minutes, respectively. 49 wt% MOF-76?LDH exhibited a high desulfurization capacity (100%), much higher than that of LDH (16.3%), MOF-76 (48%) and MOF-76 + LDH (50.3%). Because MOF-76?LDH has a special one-dimensional channel on the surface of the material, it can efficiently promote the degradation of H2O2 into hydroxyl radicals (OH) and further improve the desulfurization effect. The catalyst is easy to recycle and can be reused at least 5 times, and the catalytic effect is not significantly reduced. This provides a completely new route for the synthesis of MOF-LDH advanced functional materials.
- Li, Xiaonan,Liu, Siqi,Zhang, Hong
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p. 6269 - 6276
(2020/05/13)
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- Efficient Catalytic Oxidative Desulfurization toward Thioether and Sulfur Mustard Stimulant by Polyoxomolybdate-Resorcin[4]arene-Based Metal-Organic Materials
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The design and synthesis of effective and recyclable oxidative desulfurization catalysts is of great importance in view of environmental protection and human health. Herein, a family of polyoxomolybdate-based inorganic-organic hybrid materials, namely, [Mn(TMR4A)(H2O)4][Mo6O19]·0.5CH3CH2OH·H2O (1), [Ni(TMR4A)(H2O)4][Mo6O19]·0.5CH3CH2OH·H2O (2), [Zn(TMR4A)(H2O)4][Mo6O19]·0.5CH3CH2OH·H2O (3), and [Co2(TMR4A)2(H2O)4(β-Mo8O26)]·CH3CN·12H2O (4), were assembled by the functionalized resorcin[4]arene ligand (TMR4A) with polyoxomolybdate and metal ions under solvothermal conditions. In isostructural 1-3, the [M(TMR4A)(H2O)4]2+ species (M = MnII, NiII, ZnII) and [Mo6O19]2- anions are held together via C-H···O hydrogen bonds to give a 3D supramolecular architecture. In 4, two [Co(TMR4A)(H2O)2]2+ cations were linked by one [β-Mo8O26]4- anion to produce an attractive molecular dimer. Remarkably, 1-4, as recyclable heterogeneous catalysts, exhibit efficient catalytic oxidation desulfurization activities toward thioethers. Particularly, 1, as a representative example, features selective catalytic oxidation for sulfur mustard simulant. Moreover, their electrochemical properties were also studied.
- Guo, Ting-Ting,Ma, Jian-Fang,Yang, Jin,Yu, Ming-Yue
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supporting information
(2020/04/02)
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- Three Zr(IV)-Substituted Polyoxotungstate Aggregates: Structural Transformation from Tungstoantimonate to Tungstophosphate Induced by pH
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Three novel Zr-substituted polyoxotungstate aggregates [H2N(CH3)2]7NaH2[Zr2Sb2O3(A-α-PW9O34)2]·16H2O (1), [H2N(CH3)2]6H12[ZrSb4(OH)O2(A-α-PW8O32)(A-α-PW9O34)]2·33H2O (2), and [H2N(CH3)2]4Na11.5H4.5[Zr4W8Sb4P5O49(OH)5(B-α-SbW9O33)2]·53H2O (3) have been made in hydrothermal reactions of the [B-α-SbW9O33]9- precursor with Zr4+ cations and PO43- anions in the presence of dimethylamine hydrochloride and sodium acetate buffer (pH = 4.8) and structurally characterized. Different pH values induce structural transformation from tungstoantimonate (TA) to tungstophosphate (TP). 1 is a di-Zr-substituted sandwich-type TP, the tetranuclear heterometallic [Zr2Sb2O3]8+ entity sandwiched by two [A-α-PW9O34]9- moieties. 2 is a double sandwich-type structure, which can be perceived as two equivalent sandwiched [Sb3(PW8O32)(PW9O34)]11- further sandwiching one [Sb2Zr2(OH)2O4]4+ core to form a novel large-size sandwich-type architecture. Different from 1 and 2, 3 is a tetra-Zr-substituted sandwiched configuration, in which two [B-α-SbW9O33]9- fragments sandwich a unique 21-core Sb-P-W-Zr oxo cluster ({Zr4W8Sb4P5}). Furthermore, the catalytic oxidation of aromatic thioethers by 3 as the heterogeneous catalyst has been investigated, showing high conversion and remarkable selectivity as well as excellent recyclability.
- Li, Hai-Lou,Lian, Chen,Yang, Guo-Yu,Yin, Da-Peng
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p. 12842 - 12849
(2020/09/15)
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- Discovery of fluorescent coumarin-benzo[b]thiophene 1, 1-dioxide conjugates as mitochondria-targeting antitumor STAT3 inhibitors
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STAT3 has been extensively studied as a potential antitumor target. Though studies on regulating STAT3 mainly focus on the inhibition of STAT3 phosphorylation at Tyr705 residue, the phosphorylation at Ser727 residue of STAT3 protein is also closely associated with the mitochondrial import of STAT3 protein. N, N-diethyl-7-aminocoumarin is a fluorescent mitochondria-targeting probe. In this study, a series of STAT3 inhibitors were developed by connecting N, N-diethyl-7-aminocoumarin fluorophore with benzo [b]thiophene 1, 1-dioxide moiety. All designed compounds displayed potent anti-proliferative activity against cancer cells. The representative compound 7a was mainly accumulated in mitochondria visualized by its fluorescence. STAT3 phosphorylation was inhibited by compound 7a at both Tyr705 and Ser727 residues. Compound 7a inhibited STAT3 phosphorylation whereas had no influence on the phosphorylation levels of STAT1, JAK2, Src and Erk1/2, indicating good selectivity of compound 7a. Moreover, compound 7a down-regulated the expression of STAT3 target genes Bcl-2 and Cyclin D1, increased ROS production and remarkably reduced the mitochondrial membrane potential to induce mitochondrial apoptotic pathway. Furthermore, compound 7a in vivo suppressed breast cancer 4T1 implanted tumor growth. Taken together, these results highlighted that compound 7a might be a promising mitochondria-targeting STAT3 inhibitor for cancer therapy.
- Cai, Guiping,Yu, Wenying,Song, Dongmei,Zhang, Wenda,Guo, Jianpeng,Zhu, Jiawen,Ren, Yuhao,Kong, Lingyi
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p. 236 - 251
(2019/05/02)
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- Tailoring chemoenzymatic oxidation: Via in situ peracids
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Epoxidation chemistry often suffers from the challenging handling of peracids and thus requires in situ preparation. Here, we describe a two-phase enzymatic system that allows the effective generation of peracids and directly translate their activity to the epoxidation of olefins. We demonstrate the approach by application to lipid and olefin epoxidation as well as sulfide oxidation. These methods offer useful applications to synthetic modifications and scalable green processes.
- Re, Rebecca N.,Proessdorf, Johanna C.,La Clair, James J.,Subileau, Maeva,Burkart, Michael D.
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supporting information
p. 9418 - 9424
(2019/11/14)
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- Study on the performance and mechanism of aerobic oxidative desulfurization based on a dual-functional material possessing catalytic and adsorptive properties
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Herein, three polyoxometalates, namely K3PW12O40·10H2O, K6[α-P2W18O62]·14H2O, and K8H[P2W15V3O62]·9H2O, were successfully prepared and used in the air/n-octanaloxidative desulfurization (ODS) system. Among the compounds, the Dawson-type polyoxometalate K6[α-P2W18O62]·14H2O exhibited the best performance, with a 99.63% desulfurization ratio. Then, K6[α-P2W18O62]·14H2O was supported on graphene oxide (GO) to obtain K6P2W18O62/GO. The prepared catalysts were characterized by Fourier transform infrared spectroscopy (FTIR), 31P nuclear magnetic resonance (31P NMR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), and Boehm titration. Using K6P2W18O62/GO as a catalyst, a final sulfur removal ratio of 96.10% was achieved without extraction post-treatment due to the inherent adsorption capacity of the catalyst. In addition, the factors influencing the desulfurization process were investigated. The recovery experiment showed that the supported catalyst could be reused 5 times with slight catalyst deactivation. Finally, the reaction mechanism was proposed with the aid of gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and contrast tests.
- Dou, Shuai-yong,Wang, Rui
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p. 3226 - 3235
(2019/02/17)
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- A New Hepta-Nuclear Ti-Oxo-Cluster-Substituted Tungstoantimonate and Its Catalytic Oxidation of Thioethers
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A neoteric hepta-nuclear Ti-oxo-cluster-substituted tetrameric tungstoantimonate [H2N(CH3)2]22Na18{Ti7O6(SbW9O33)4}2·124H2O (1) has hydrothermally been synthesized and tested by single-crystal/powder X-ray diffraction, IR spectra, and thermal analysis. The glamorous feature of this tetrameric polyoxoanion is an uncommon hepta-nuclear Ti-oxo-cluster octahedron [Ti7O6]16+ enclosed in four [B-α-SbW9O33]9- building units. As a heterogeneous catalyst, the investigation on catalytic oxidation with H2O2 for multiple thioethers indicated that 1 possesses high conversion and remarkable selectivity. Additionally, 1 exhibits good stability and excellent recyclability.
- Li, Hai-Lou,Lian, Chen,Yin, Da-Peng,Jia, Zhi-Yu,Yang, Guo-Yu
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p. 376 - 380
(2019/01/09)
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- Sonochemical degradation of benzothiophene (BT) in deionized water, natural water and sea water
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This paper deals with the sonochemical water treatment of polycyclic aromatic sulfur hydrocarbons (PASHs), one of the most common impurities found in waste water coming from petroleum industry. The best fit of the experimental data appears to be the kinetic parameters determined using the Michaelis-Mentonmodel in the concentrations range of the study. For the initial increase in the degradation rates, it is simply considered that the more the bulk concentration increases, the more the concentration in the interfacial region increases. This will be explained by Michaelis-Menton kinetics. The influence of organic compounds in the water matrix as a mixture with Benzothiophene (BT) was also evaluated. The results indicated that BT degradation is unaffected by the presence of bisphenol A (BPA). Finally, the results indicated that ultrasonic action is involved in oxidation rather than pyrolitic processing in the BT sonochemical degradation.
- Al-Zaydi, Khadijah M.,Petrier, Christian,Mousally, Sameera M.M.,Arab, Sana T.,Refat, Moamen S.
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- Highly stable polyoxometalate-resorcin[4]arene-based inorganic-organic complexes for catalytic oxidation desulfurization
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Self-assembly of a resorcin[4]arene-based ligand (TMR4A) with metal salts and H3PMo12O40·xH2O offers two isostructural complexes, namely, [Ni2Cl(TMR4A)2(CH3CN)2]·[PMo12O40]·4CH3CN (1) and [Co2Cl(TMR4A)2(CH3CN)2]·[PMo12O40]·4CH3CN (2). In both 1 and 2, one Cl? anion bridges two metal cations, and each metal cation is further chelated by four 2-mercaptopyridine N-oxide groups of one TMR4A, producing a [M2Cl(TMR4A)2]3+ dimer (M?=?Ni or Co). The negative [PMo12O40]3? as a counter-anion balances the positive charge. Markedly, 1 and 2 exhibit high stability in aqueous solutions with different pH values and in organic solvents. Remarkably, the efficient heterogeneous catalytic capability for oxidative desulfurization was studied by suing 1 and 2 as recycled catalysts. Moreover, the electrochemical behaviors of the two compounds were discussed as well.
- Yu, Ming-Yue,Yang, Jin,Xu, Xianxiu,Ma, Jian-Fang,Wang, Zhenxing
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- 1,3-disubstituted ketene compound and application thereof
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The invention relates to a 1,3-disubstituted ketene compound with a structure as shown in a formula (I) and application thereof. The compound mainly activates a PPAR (Peroxisome Proliferators-Activated Receptor) alpha, and also has excitation activity for PPPA delta and PPPA gamma. The 1,3-disubstituted ketene compound can be used for treating various diseases related to the PPAR regulation abnormality, such as NASH (nonalcoholic steatohepatitis), and particularly treating nonalcoholic hepatitis, also has potentials for treating diabetes, obesity, fibrotic diseases, cardiovascular diseases (comprising a heart failure, atherosclerosis and the like), kidney diseases (comprising chronic nephrosis, a kidney failure and the like), brain degenerative diseases (comprising the alzheimer disease and the like) and the like, and has higher application value. The formula is shown in the description.
- -
-
Paragraph 0204; 0205
(2018/11/03)
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- Efficient molybdenum catalyzed chemoselective, solvent-free oxidation of sulfides to sulfones at room temperature
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An effcient and reusable molybdenum-based catalyst has been prepared by tethering dioxomolybdenumacetylacetonate complex, MoO2(acac)2, via postsynthesis modifcation of zeolite beta. The catalyst has been characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and inductively coupled plasma (ICP). The catalyst exhibited very high activity for the selective oxidation of sulfdes to sulfones at room temperature. The catalyst can be recycled and reused four times without signifcant loss of activity.
- Hadigavabar, Ali Dadashi,Tabatabaeian, Khalil,Zanjanchi, Mohammad Ali,Mamaghani, Manouchehr
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p. 3829 - 3833
(2018/05/24)
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- Organophosphonate-Functionalized Lanthanopolyoxomolybdate: Synthesis, Characterization, Magnetism, Luminescence, and Catalysis of H2O2-Based Thioether Oxidation
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A novel class of organophosphonate-based polyoxomolybdate derivatives, K4H5[Ln3(H2O)14{(Mo8O24)(O3PCH2COO)3}2]·23H2O (Ln = Gd (1Gd), Tb (2Tb), Dy (3Dy)), have been fully investigated by a few characterization methods such as single-crystal X-ray crystallography, XRPD, elemental analysis, TGA, and IR spectra. The magnetic properties of 1Gd, 2Tb, and 3Dy were investigated, as well as the solid-state luminescence properties of 2Tb and 3Dy. The catalysis properties of 1Gd, 2Tb, and 3Dy for thioether oxidization have been investigated using hydrogen peroxide (H2O2) as an oxidant. The catalysis study demonstrated the efficient and selective conversion of various thioethers to their corresponding sulfones in excellent yields.
- Wang, Jiawei,Niu, Yanjun,Zhang, Meng,Ma, Pengtao,Zhang, Chao,Niu, Jingyang,Wang, Jingping
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p. 1796 - 1805
(2018/02/23)
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- Hydroconversion of Oxidation Products of Sulfur-Containing Aromatic Compounds
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Hydroconversion of benzo- and dibenzothiophene sulfone on a Ni–Mo sulfide catalyst based on mesoporous aluminosilicate Al-HMS and on unsupported catalysts prepared in situ in the course of decomposition of poorly soluble precursors (molybdenum hexacarbonyl, nickel naphthenate) was investigated. Hydrogenation of sulfones was performed at 250°С, 340°С, and 380°С and elevated СО pressure in the presence of H2O ensuring in situ generation of H2 via water-gas shift reaction. The products that are formed by oxidation of organic sulfur compounds and remain in the hydrocarbon medium (mainly sulfones) will not significantly affect the subsequent hydrotreatment since under the conditions of hydroprocesses, they transform into the corresponding benzo- and dibenzothiophenes, which undergo the subsequent hydrodesulfurization to form mono- and diaromatic hydrocarbons.
- Vutolkina,Akopyan,Glotov,Kotelev,Maksimov,Karakhanov
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p. 981 - 989
(2018/08/31)
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- A Crown-Shaped Ru-Substituted Arsenotungstate for Selective Oxidation of Sulfides with Hydrogen Peroxide
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An acetate-bridged Ru-substituted arsenotungstate [H2N(CH3)2]14[As4W40O140{Ru2(CH3COO)}2]?22 H2O (1) has been synthesized and structurally characterized. Four Ru atoms occupy the respective lacunary S2 sites of the crown-shaped polyanion [As4W40O140]28?, and each Ru atom is coordinated by one As atom and five μ2-O atoms, comprising four from the S2 site and one from the acetate ligand. To the best of our knowledge, this coordination of the Ru atom, with an Ru?As bond length of 2.377(3)–2.387(3) ?, is unprecedented in polyoxometalate (POM) chemistry. Notably, 1 exhibits high efficiency, excellent selectivity, and good recyclability for the oxidation of sulfides with hydrogen peroxide (H2O2). Catalytic oxidation of various sulfides in the presence of 1 gives superior conversion and selectivity for sulfones in acetonitrile, whereas sulfoxides are obtained in methanol.
- Han, Mengdan,Niu, Yanjun,Wan, Rong,Xu, Qiaofei,Lu, Jingkun,Ma, Pengtao,Zhang, Chao,Niu, Jingyang,Wang, Jingping
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p. 11059 - 11066
(2018/08/09)
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- Preparation, characterization, and catalytic performances of a pyrazine dicarboxylate-bridging rare-earth-containing polytungstoarsenate aggregate for selective oxidation of thiophenes and deep desulfurization of model fuels
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A new polytungstoarsenate, K6LiH6[Ce4(H2O)14(pzdc)(H2pzdc)As3W29O103]·22H2O (1) (H2pzdc = 2,3-pyrazinedicarboxylic acid), was synthesized via a conventional aqueous solution method. In this synthetic approach, the organic ligand pyrazine dicarboxylate acid was introduced into the arsenotungstate system. The synthesized compound 1 was well characterized using elemental analysis, IR spectroscopy, UV-vis spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction. The catalytic activity of compound 1 was tested in acetonitrile to oxidize organosulfur compounds (benzothiophene (BT) and dibenzothiophene (DBT)) with hydrogen peroxide as an oxidant at room temperature. Two substrates were oxidized to their corresponding sulfones with high conversion and selectivity. Taking advantage of this remarkable catalytic move, the 1/H2O2/CH3CN system was further utilized in the oxidation of model fuels (MF) including a mixture of BT and DBT in octane. As a result, the organosulfur compounds in the model fuels were fully converted into their corresponding sulfones. Furthermore, the fluorescence properties of 1 were also investigated.
- Niu, Yanjun,Xu, Qiaofei,Wang, Yuan,Li, Zhao,Lu, Jingkun,Ma, Pengtao,Zhang, Chao,Niu, Jingyang,Wang, Jingping
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p. 9677 - 9684
(2018/08/06)
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- Method for preparing aromatic ring thiophthene-1,1-dioxide
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The invention provides a method for preparing aromatic ring thiophthene-1,1-dioxide. The method comprises the following steps: carrying out one-step cyclization on an ortho-position substituted aromatic ring and sodium alkylsulfinate, and carrying out a dehydration reaction, thereby obtaining the aromatic ring thiophthene-1,1-dioxide. The ortho-position substituted aromatic ring is of a structureof a compound of formula (I) as shown in the description. Compared with synthesis routes of a conventional method, the method for preparing the aromatic ring thiophthene-1,1-dioxide, which is providedby the invention, is easy in raw material obtaining, low in cost, gentle in reaction, easy to control, small in waste generation, small in pollution, simple in aftertreatment and in addition applicable to preparation of all types of aromatic ring thiophthene-1,1-dioxide, novel strategies are provided for the aromatic ring thiophthene-1,1-dioxide, and high production and application values can bemade.
- -
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Paragraph 0052; 0054; 0058
(2019/01/13)
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- Synthesis and characterization of PMoV/Fe3O4/g-C3N4 from melamine: An industrial green nanocatalyst for deep oxidative desulfurization
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A facile approach to the preparation of a novel magnetically separable H5PMo10V2O40/Fe3O4/g-C3N4 (PMoV/Fe3O4/g-C3N4) nanocomposite by chemical impregnation is demonstrated. The prepared nanocomposite was characterized and its acidity was measured by potentiometric titration. PMoV/Fe3O4/g-C3N4 showed high catalytic activity in the selective oxidative desulfurization of sulfides to their corresponding sulfoxides or sulfones. The catalytic oxidation of a dibenzothiophene (DBT)-containing model oil and that of real oil were also studied under optimized conditions. In addition, the effects of various nitrogen compounds, as well as the use of one- and two-ring aromatic hydrocarbons as co-solvents, on the catalytic removal of sulfur from DBT were investigated. The catalyst was easily separated and could be recovered from the reaction mixture by using an external magnetic field. Additionally, the remaining reactants could be separated from the products by simple decantation if an appropriate solvent was chosen for the extraction. The advantages of this nanocatalyst are its high catalytic activity and reusability; it can be used at least four times without considerable loss of activity.
- Rafiee, Ezzat,Khodayari, Maryam
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p. 458 - 468
(2017/04/04)
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- Ultrasound-assisted oxidative desulfurization process of liquid fuel by phosphotungstic acid encapsulated in a interpenetrating amine-functionalized Zn(II)-based MOF as catalyst
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In this work, ultrasound-assisted oxidative desulfurization (UAOD) of liquid fuels performed with a novel heterogeneous highly dispersed Keggin-type phosphotungstic acid (H3PW12O40, PTA) catalyst that encapsulated into an amino-functionalized MOF (TMU-17-NH2). The prepared composite exhibits high catalytic activity and reusability in oxidative desulfurization of model fuel. Ultrasound-assisted oxidative desulfurization (UAOD) is a new way to performed oxidation reaction of sulfur-contain compounds rapidly, economically, environment-friendly and safely, under mild conditions. Ultrasound waves can be apply as an efficient tool to decrease the reaction time and improves oxidative desulfurization system performance. PTA@TMU-17-NH2 could be completely performed desulfurization of the model oil by 20?mg of catalyst, O/S molar ratio of 1:1 in presence of MeCN as extraction solvent. The obtained results indicated that the conversions of DBT to DBTO2 achieve 98% after 15?min in ambient temperature. In this work, we prepared TMU-17-NH2 and PTA/TMU-17-NH2 composite by ultrasound irradiation for first time and employed in UAOD process. Prepared catalyst exhibit an excellent reusability without PTA leaching and loss of activity.
- Afzalinia, Ahmad,Mirzaie, Abbas,Nikseresht, Ahmad,Musabeygi, Tahereh
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p. 713 - 720
(2016/07/21)
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- 1,1,2,2-Tetrahydroperoxy-1,2-diphenylethane as new oxidant for chemoselective and catalyst free oxidation of sulfides to sulfoxides and sulfones
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A catalyst free and chemoselective oxidation of sulfides to sulfoxides or sulfones was developed using 1,1,2,2-tetrahydroperoxy-1,2-diphenylethane as a new oxidant. This scope has shown the achievement of various sulfoxides and sulfones which were obtained selectively in high yields at room temperature.
- Khosravi, Kaveh,Naserifar, Shirin,Mahmoudi, Boshra,Khalaji, Kobra
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p. 316 - 321
(2017/02/18)
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- Reduced graphene oxide: A metal-free catalyst for aerobic oxidative desulfurization
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Nanocarbons have been extensively used as metal-free alternatives to metal catalysts in many oxidative processes owing to their functional groups or defects, which have the activation ability toward oxygen molecules. Herein, reduced graphene oxide (rGO) could be used as catalysts in oxidative desulfurization reactions for the first time to remove sulfur-containing compounds from fuels. Superior catalytic activity and stability are obtained in the aerobic oxidative desulfurization process catalyzed by rGO. A broad range of sulfur-containing aromatic substrates could be removed effectively in this catalytic system. Carbonyl groups have proved to play crucial roles during the oxidation process based on an XPS analysis, a chemical titration method and a series of comparative experiments. The chemically active defects are also beneficial to the catalytic performance because carbonyl groups could be generated in situ on these defects under the reaction conditions. Based on the EPR results, a radical pathway is proposed. Oxygen molecules could interact with the carbon atoms adjacent to carbonyl groups to form adsorbed super oxygen anion radicals (rGO-OO?-), which then attack the adjacent sulfur-centered cation radicals and generate the final product sulfone.
- Gu, Qingqing,Wen, Guodong,Ding, Yuxiao,Wu, Kuang-Hsu,Chen, Chengmeng,Su, Dangsheng
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p. 1175 - 1181
(2017/03/17)
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- Preparation, characterization and catalytic performance of HPW/aEVM catalyst on oxidative desulfurization
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Expanded vermiculite (EVM) was prepared, treated with acid (aEVM) and incorporated with H3PW12O40 (HPW) by an ordinary impregnation method. Various characterizations of the HPW/aEVM catalyst indicated that the HPW was dispersed homogeneously on the aEVM support. The catalytic activity of the HPW/aEVM catalyst was evaluated in the catalytic oxidation process of dibenzothiophene (DBT), and the optimal reaction conditions were investigated, including the loading quantity of the phosphotungstic acid, the reaction temperature and time, the O/S (H2O2/sulfur) molar ratio, and the catalyst dosage. Under the experimental conditions, the sulfur removal rate for model oil was almost 100%. After 7 recycles, the loss of catalytic activity was only 99.95 to 98.06%.
- Huang, Pengcheng,Luo, Guangqin,Kang, Lihua,Zhu, Mingyuan,Dai, Bin
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p. 4681 - 4687
(2017/02/05)
-
- Catalytic performance of ammonium salt of molybdenum heteropoly acid supported silica for oxidative desulfurization of benzothiophene, dibenzothiophene and 4,6-dimethyldibenzothiophene in model oil
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An ammonium salt of molybdenum heteropoly acid was loaded on silica support (HPA-SiO2), used as catalyst in oxidative desulfurization for removing benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) from model oil. The structural properties of prepared catalyst were studied by using various analytical techniques; Fourier transforms infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The results showed that the ammonium salt of molybdenum heteropoly acid highly dispersed on SiO2. The final catalyst exhibits good catalytic activity of oxidative desulfurization. The 94.6 % of thiophene compounds of the model oil were removed under optimal conditions; temperature at 80 °C, reaction time 100 min. The oxidation is decreased in order of DBT > 4,6-DMDBT > BT.
- Pant, Deeptiraj,Thakur, Ramswaroop Singh,Lal, Sunder
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p. 1723 - 1727
(2017/06/27)
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- The Polyoxovanadate-Based Carboxylate Derivative K6H[VV17VIV12(OH)4O60(OOC(CH2)4COO)8]·nH2O: Synthesis, Crystal Structure, and Catalysis for Oxidation of Sulfides
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The high-nuclearity polyoxovanadate-based carboxylate derivative K6H[VV17VIV12(OH)4O60(OOC(CH2)4COO)8]·nH2O (1) has been successfully synthesized by conventional aqueous methods and structurally characterized. The [VV17VIV12(OH)4O60(OOC(CH2)4COO)8]7- polyanion is built up from three cages: one {VV17(OH)4O44} cage and two identical [(VIV3O6)2(OOC(CH2)4COO)4]8- cages. Of the three cages, the {VV17(OH)4O44} is a purely inorganic polyoxovanadate cluster, whereas each of the [(VIV3O6)2(OOC(CH2)4COO)4]8- cages is a vanadium-based organic-inorganic hybrid cluster framed via four adipate ligands linking simultaneously to two triangular {V3} units. The two [(VIV3O6)2(OOC(CH2)4COO)4]8- cages are covalently attached to the central {VV17(OH)4O44} cage via V-O-V bonds in a linear arrangement, resulting in a {V29}-based hybrid cluster skeleton. The catalytic properties of compound 1 for the oxidation of sulfides by tert-butyl hydroperoxide were investigated, and the result indicates that 1 exhibits excellent catalytic activity for the oxidation of sulfides under mild conditions.
- Wang, Ke,Niu, Yanjun,Zhao, Dongyan,Zhao, Yanxin,Ma, Pengtao,Zhang, Dongdi,Wang, Jingping,Niu, Jingyang
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p. 14053 - 14059
(2017/11/27)
-
- Controllable Synthesis of Lindqvist Alkoxopolyoxovanadate Clusters as Heterogeneous Catalysts for Sulfoxidation of Sulfides
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Six alkoxohexavanadate-based Cu- or Co-POVs [Cu(dpa)(acac)(H2O)]2[V6O13(OMe)6] (1), [Cu(phen)(acac)(MeOH)]2[V6O13(OMe)6] (2), [Co(dpa)(acac)2]2[V6O13(OMe)6]·2MeOH (3), [Co(phen)(acac)2]2[V6O13(OMe)6] (4), [Cu(dpa)(acac)]2[VIV2VV4O12(OMe)7] (5), and [Cu(dpa)(acac)(MeOH)]2[VIV2VV4O11(OMe)8] (6) (POV = polyoxovanadate; dpa = 2,2′-dipyridine amine; phen = 1,10-phenanthroline; acac = acetylacetone anion) have been synthesized by controlling the reaction conditions and characterized by single-crystal X-ray diffraction and powder X-ray diffraction analyses, FT-IR spectroscopy, element analyses, and X-ray photoelectron spectroscopy. In compounds 1-4 and 6, Cu or Co complexes and alkoxohexavanadate anions are assembled through electrostatic interactions. Differently, in compound 5, seven-methoxo-substituted Lindqvist-type [V6O12(OMe)7]2- are bridged to Cu complex via terminal O atoms by coordination bonds. All compounds 1-6 exhibit excellent heterogeneous catalytic performance in oxidative desulfurization and CEES ((2-chloroethyl) ethyl sulfide, a sulfur mustard simulant) abatement with H2O2 as oxidant. Among them, the catalytic activity of 6 [conv. of DBT (dibenzothiophene) up to 100% in 6 h; conv. of CEES reached 100% and selectivity of CEESO ((2-chloroethyl) ethyl sulfoxide) up to 85% after 4 h] outperforms others and can be reused without losing its activity.
- Li, Ji-Kun,Dong, Jing,Wei, Chuan-Ping,Yang, Song,Chi, Ying-Nan,Xu, Yan-Qing,Hu, Chang-Wen
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p. 5748 - 5756
(2017/05/22)
-
- A Polyoxovanadate-Resorcin[4]arene-Based Porous Metal-Organic Framework as an Efficient Multifunctional Catalyst for the Cycloaddition of CO2 with Epoxides and the Selective Oxidation of Sulfides
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In this work, we report a new polyoxovanadate-resorcin[4]arene-based metal-organic framework (PMOF), [Co2L0.5V4O12]·3DMF·5H2O (1), assembled with a newly functionalized wheel-like resorcin[4]arene ligand (L). 1 features an elegant porous motif and represents a rare example of PMOFs composed of both a resorcin[4]arene ligand and polyoxovanadate. Remarkably, 1 shows open V sites in the channel, which makes 1 an efficient heterogeneous Lewis acid catalyst for the cycloaddition of carbon dioxide to epoxides with high conversion and selectivity. Strikingly, 1 also exhibits high catalytic activity for the heterogeneous oxidative desulfurization of sulfides. Particularly, the heterogeneous catalyst 1 can be easily separated and reused with good catalytic activity.
- Lu, Bing-Bing,Yang, Jin,Liu, Ying-Ying,Ma, Jian-Fang
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p. 11710 - 11720
(2017/10/13)
-
- Rate and Selectivity Control in Thioether and Alkene Oxidation with H2O2 over Phosphonate-Modified Niobium(V)–Silica Catalysts
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Supported metal oxide catalysts are versatile materials for liquid-phase oxidations, including alkene epoxidation and thioether sulfoxidation with H2O2. Periodic trends in H2O2 activation was recently demonstrated for alkene epoxidation, highlighting Nb-SiO2 as a more active and selective catalyst than Ti-SiO2. Three representative catalysts are studied consisting of NbV, TiIV, and ZrIV on silica, each made through a molecular precursor approach that yields highly dispersed oxide sites, for thioanisole oxidation by H2O2. Initial rates trend Nb>Ti?Zr, as for epoxidation, and Nb outperforms Ti for a number of other thioethers. In contrast, selectivity to sulfoxide vs. sulfone trends Ti>Nb?Zr at all conversions. Modifying the Nb-SiO2 catalyst with phenylphosphonic acid does not completely remove sulfoxidation reactivity, as it did for photooxidation and epoxidation, and results in an unusual material active for sulfoxidation but neither epoxidation nor overoxidation to the sulfone.
- Thornburg, Nicholas E.,Notestein, Justin M.
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p. 3714 - 3724
(2017/09/12)
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- SULFONYLUREAS AND RELATED COMPOUNDS AND USE OF SAME
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ABSTRACT The present invention provides for certain sulfonyl ureas and related compounds which have advantageous properties and show useful activity in the inhibition of activation of the NLRP3 inflammasome. Such compounds are useful in the treatment of a wide range of disorders in which the inflammation process, or more specifically the NLRP3 inflammasome, have been implicated as being a key factor.
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Page/Page column 115; 116
(2016/09/15)
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- Alkylaminophosphazenes as Efficient and Tuneable Phase-Transfer Agents for Polyoxometalate-Catalysed Biphasic Oxidation with Hydrogen Peroxide
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Alkylaminophosphazenes (RPN) are efficient and tuneable phase-transfer agents for environmentally benign biphasic oxidation with hydrogen peroxide catalysed by polyoxometalates (POMs). Substituent groups on the phosphazene ring can be varied to modify the
- Craven, Michael,Yahya, Rana,Kozhevnikova, Elena F.,Robertson, Craig M.,Steiner, Alexander,Kozhevnikov, Ivan V.
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p. 200 - 208
(2016/01/25)
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- A Mn(III) polyoxotungstate in the oxidation of organosulfur compounds by H2O2 at room temperature: An environmentally safe catalytic approach
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The tetrabutylammonium (TBA) salt of a Keggin-type polyoxometalate (POM), with the chemical formula TBA4H2[BW11Mn(H2O)O39]·H2O, TBABW11Mn, was evaluated as a catalyst in the oxidation by hydrogen peroxide of several organosulfur compounds, namely benzothiophene (BT), 2-methylbenzothiophene (2-MBT), 3-methylbenzothiophene (3-MBT), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT) and 4,6-diethyldibenzothiophene (4,6-DEDBT), in acetonitrile at room temperature. All compounds were oxidized to their corresponding sulfones with high conversion and selectivity. Following the excellent results achieved, the BW11Mn/H2O2 in CH3CN system was tested in the oxidation of model fuels (MFs) consisting of a mixture of BTs and DBTs in hexane (MF1 containing mainly BTs and MF2 containing predominantly DBTs). In both cases, the organosulfur compounds from the model fuels were fully converted into their corresponding sulfones. Envisaging the development of a promising desulfurization procedure, the extraction of sulfur compounds from MF2 was attempted after the catalytic oxidation process. More than 98 mol% was removed using an ethanol/H2O mixture.
- Duarte, Tiago A.G.,Pires, Sónia M.G.,Santos, Isabel C.M.S.,Sim?es, Mário M.Q.,Neves, M. Gra?a P.M.S.,Cavaleiro, Ana M.V.,Cavaleiro, José A.S.
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p. 3271 - 3278
(2016/05/24)
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- An organic-inorganic hybrid based on an Anderson-type polyoxometalate immobilized on PVA as a reusable and efficient nanocatalyst for oxidative desulphurization of gasoline
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In the present work, an organic-inorganic hybrid based on an Anderson-type polyoxometalate ((C4H9)4N)6Mo7O24 was synthesized and immobilized on poly vinyl alcohol (PVA) via a sol-gel method. This synthesized nanocomposite was characterized by FT-IR, XRD, SEM and UV-vis spectroscopy. The catalytic activity of this hybrid nanocomposite was tested on oxidative desulphurization (ODS) of model sulfur compounds and actual gasoline. The ODS was performed using different polyoxometalates as catalyst and CH3COOH/H2O2 as oxidant. The experimental results show that the supported polyoxometalate ((C4H9)4N)6Mo7O24/PVA catalyst is more active than the unsupported polyoxometalate catalysts. The oxidation reactivity of the catalysts depends on the type of countercation: ((C4H9)4N)+ > NH4+ > Na+. The sulfur-containing compounds, such as thiophene (Th), benzothiophene (BT) and dibenzothiophene (DBT) were oxidized to the corresponding sulfones. The reactivity order of the model sulfur compounds is: DBT > BT > Th. The effects of the reaction time, reaction temperature, dosage and nature of catalyst and concentration of hydrogen peroxide were investigated. The ((C4H9)4N)6Mo7O24/PVA also shows high selectivity for DBT oxidation desulphurization. The selective desulfurization ratio reaches 94% with ((C4H9)4N)6Mo7O24/PVA under the reaction conditions of 40 °C, 2 h. The kinetic parameters of the oxidation of model sulfur compounds were studied. The oxidation rate was interpreted with first-order kinetics. The advantages of this method lie in its mild conditions, low cost, large scale, simplicity and environmentally friendly route.
- Rezvani,Nia Asli, M. Ali,Oveisi,Babaei,Qasemi,Khandan
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supporting information
p. 53069 - 53079
(2016/06/14)
-
- Extractive and oxidative desulfurization of model oil in polyethylene glycol
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The polyethylene glycol 200 (PEG-200) was explored as a green solvent for extractive and catalytic oxidative desulfurization (ODS) process. ODS experiments were conducted using model oil with SeO2 as catalyst and H2O2 as an oxidant. The desulfurization system was very efficient for the removal of DBTs under mild conditions. The reaction conditions such as the amount of PEG-200, temperature, mole ratio of H2O2 and sulfur compound were investigated. The different sulfur substrates removed by this desulfurization system were also investigated and the following order was found: dibenzothiophene (DBT) > 4,6-dimethyl dibenzothiophene (4,6-DMBT) > benzothiophene (BT). The desulfurization system could be used 7 times without significant decrease in activity. The possible catalytic mechanism seems that peroxyseleninic acid may be considered as the true oxidative agent formed from hydrogen peroxide and selenium dioxide, which translated the DBT to the corresponding sulfone.
- Wang, Jianlong,Zhao, Rijie,Han, Baixin,Tang, Nan,Li, Kaixi
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p. 35071 - 35075
(2016/06/13)
-