825-44-5Relevant articles and documents
Surfactant-encapsulated high-nuclear polyoxometalate complexes for catalytic oxidative desulfurization of model oil
Wang, Tingting,Lu, Ying,Wu, Hongli,Wang, Enbo
, p. 13 - 18 (2016)
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.
Trifluoromethanesulfonic acid-based DESs as extractants and catalysts for removal of DBT from model oil
Mao, Chunfeng,Zhao, Rongxiang,Li, Xiuping,Gao, Xiaohan
, p. 12805 - 12811 (2017)
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%.
Hexagonal nanoplates of high-quality γ-gallium oxide: Controlled synthesis and good heterogeneous catalytic performance for thiophenes
Yang, Zun,Song, Le Xin,Wang, Ya Qian,Ruan, Mao Mao,Teng, Yue,Xia, Juan,Yang, Jun,Chen, Shan Shan,Wang, Fang
, p. 2914 - 2921 (2018)
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.
Deep oxidative desulfurization of dibenzothiophene in simulated oil and real diesel using heteropolyanion-substituted hydrotalcite-like compounds as catalysts
Yu, Fengli,Wang, Rui
, p. 13691 - 13704 (2013)
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).
Boosting Oxidative Desulfurization of Model and Real Gasoline over Phosphotungstic Acid Encapsulated in Metal–Organic Frameworks: The Window Size Matters
Wang, Xu-Sheng,Li, Lan,Liang, Jun,Huang, Yuan-Biao,Cao, Rong
, p. 971 - 979 (2017)
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.
Highly efficient extraction and oxidative desulfurization system using Na7H2LaW10O36·32-H 2O in [bmim]BF4 at room temperature
Xu, Junhua,Zhao, Shen,Chen, Wei,Wang, Miao,Song, Yu-Fei
, p. 4775 - 4781 (2012)
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.
A new organic-inorganic hybrid based on dimeric [Mn2V22O64]10 - Polyoxoanion as catalyst for oxidation of sulfides
Wang, Ting-Ting,Lu, Ying,Liu, Ding,Wang, En-Bo
, p. 47 - 51 (2016)
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.
Deep desulfurization of fuels based on an oxidation/extraction process with acidic deep eutectic solvents
Yin, Jingmei,Wang, Jinping,Li, Zhuo,Li, Dan,Yang, Guang,Cui, Yingna,Wang, Ailing,Li, Changping
, p. 4552 - 4559 (2015)
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.
Oxidative desulfurization (ODS) of organosulfur compounds catalyzed by peroxo-metallate complexes of WOx-ZrO2: Thermochemical, structural, and reactivity indexes analyses
Torres-Garcia,Galano,Rodriguez-Gattorno
, p. 201 - 208 (2011)
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.
Directional self-assembly of exfoliated layered europium hydroxide nanosheets and Na9EuW10O36·32H 2O for application in desulfurization
Wang, Xiaoting,Chen, Wei,Song, Yu-Fei
, p. 2779 - 2786 (2014)
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
