Micro-mesoporous ZK-1 molecular sieves with different Si/Al ratios were used as supports for binary Co-Mo hydrodesulfurization（HDS） catalysts.The CoMo/ZK-1 catalysts were prepared using an over-loading impregnation ...Micro-mesoporous ZK-1 molecular sieves with different Si/Al ratios were used as supports for binary Co-Mo hydrodesulfurization（HDS） catalysts.The CoMo/ZK-1 catalysts were prepared using an over-loading impregnation method,and characterized using N2 physisorption,X-ray diffraction,temperature-programmed NH3 desorption,temperature-programmed reduction（TPR）,ultraviolet-visible diffuse reflectance spectroscopy,and high-resolution transmission electron microscopy（HRTEM）.The results show that the CoMo/ZK-1 catalysts have high surface areas（～700 m^2/g）,large pore volumes,and hierarchical porous structures,which promote the dispersion of Co and Mo oxide phases on the ZK-1 supports.The TPR results show that the interactions between the Co and Mo oxide phases and the ZK-1 support are weaker than those in the CoMo/γ-Al2O3 catalyst.The HRTEM results show that the CoMo/ZK-1 catalysts have better MoS2 dispersion and more active edge sites.The catalysts were tested in HDS of dibenzothiophene.Under mild reaction conditions,the activity of Co and Mo sulfides supported on ZK-1 was higher than those of Co and Mo sulfides supported on ZSM-5,A1KIT-1,and γ-Al2O3.展开更多
Two novel V-shaped symmetric chromophores： E-2,8-bis（4-vinyl-4-carbazol-9-yl）diben- zothiophene （abbreviated as SK-G1） and E-2,8-bis（4-vinyl-4-triphenylamino） dibenzothiophene （abbreviated as ST-G1） have been...Two novel V-shaped symmetric chromophores： E-2,8-bis（4-vinyl-4-carbazol-9-yl）diben- zothiophene （abbreviated as SK-G1） and E-2,8-bis（4-vinyl-4-triphenylamino） dibenzothiophene （abbreviated as ST-G1） have been synthesized and characterized. Their two photon absorption properties were measured by the open-aperture femtosecond Z-scan technique and the nanosecond nonlinear optical transmission （NLT）, respectively, when pumped by Ti： sapphire laser at 750 nm and 800 nm.展开更多
Polychlorinated dibenzothiophenes(PCDTs)and their corresponding sulfone(PCDTO2)compounds are a group of important persistent organic pollutants.In the present study,geometrical optimization and subsequent calculations...Polychlorinated dibenzothiophenes(PCDTs)and their corresponding sulfone(PCDTO2)compounds are a group of important persistent organic pollutants.In the present study,geometrical optimization and subsequent calculations of electrostatic potentials(ESPs)on molecular surface have been performed for all 135 PCDTs and 135 PCDTO2 congeners at the HF/6-31G*level of theory.A number of statistically-based parameters have been extracted.Linear relationship between gas-chromatographic retention index(RI)and the structural descriptors have been established by multiple linear regression.The result shows that two descriptors derived from positive electrostatic potential on molecular surface,■andπ,together with the molecular volume(Vmc)and the energy of the lowest unoccupied molecular orbital(ELUMO)can be well used to express the quantitative structure-retention relationship(QSRR)of PCDTs and PCDTO2.Predictive capability of the two models has been demonstrated by leave-one-out cross-validation with the cross-validated correlation coefficient(RCV)of 0.996 and 0.997,respectively.Furthermore,the predictive power of the models is further examined for the external test set.Correlation coefficients(R)between the observed and predicted RI values for the external test set are 0.997 and0.998,respectively,validating the robustness and good prediction of our model.The QSRR model established may provide again a powerful method for predicting chromatographic properties of aromatic organosulfur compounds.展开更多
Aromatic fractions of 140 oils and condensates that originated from different types of source rocks （marine shale,terrestrial shale and marine carbonate） were analyzed using gas chromatographymass spectrometry （GC...Aromatic fractions of 140 oils and condensates that originated from different types of source rocks （marine shale,terrestrial shale and marine carbonate） were analyzed using gas chromatographymass spectrometry （GC-MS） to investigate the relative distributions of methylated dibenzothiophenes with respect to thermal maturity.The positions of methyl groups of trimethyldibenzothiophene isomers （TMDBTs） including those used in the definition of maturity indicator TMDBT index in previous studies were firmly identified by co-elution of internal standards in GC-MS analysis and by comparing with reported retention indices.A new maturity ratio related to dimethyldibenzothiophenes （DMDBTs） is proposed on the basis of the differences in thermodynamic stability among different DMDBT isomers.Another maturity index （TMDBT-I2） based on TMDBTs is also suggested on the basis of our empirical observations and presumed thermodynamic stability of TMDBT isomers.These two newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratio and TMDBT-I2 correlate well with MDR （4-/1-methyldibenzothiophene）and 2,4-/1,4-DMDBT ratios,suggesting their common chemical reaction mechanisms and similar behavior with increasing maturity.Therefore,they can be effectively applied for maturity assessments.Furthermore,the TMDBTs related maturity parameters are more reliable for over-mature oils and condensates due to the relatively higher concentrations of thermodynamically unstable TMDBT isomers,i.e.1,4,6-,1,4,8-and 3,4,6-TMDBT in this study than those of 1-methyldibenzothiophene （1-MDBT） or 1,4-DMDBT.In contrast with 4,6-/1,4-DMDBT,the newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratios for oils that originated from different types of source rocks have approximately same relationship with the oil maturity （Rc %）.This suggests that the lithology and organic facies may have relatively less influence on （2,6 ＋ 3,6）-/1,4-DMDBT ratio compared to 4,6-/1,4-DMDBT.The maturity parameters based on methylated dibenzothiophenes are particularly useful in the maturity assessments of post-and over-mature oils and condensates and can complement maturity indicators based on steranes and terpanes.展开更多
A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene（DBT） was isolated from diesel contaminated soil.The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7（NCBI ...A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene（DBT） was isolated from diesel contaminated soil.The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7（NCBI GenBank Accession No.GQ496620） using 16S rDNA gene sequence analysis.The desulfurized product of DBT,2-hydroxybiphenyl（2HBP）,was identified and confirmed by high performance liquid chromatography analysis and gas chromatography-mass spectroscopy analysis respectively.The desulfurization kinetics revealed that DMT-7 started desulfurization of DBT into 2HBP after the lag phase of 24 hr,exponentially increasing the accumulation of 2HBP up to 15 days leading to approximately 60% desulfurization of the DBT.However,further growth resulted into DBT degradation.The induced culture of DMT-7 showed shorter lag phase of 6 hr and early onset of stationary phase within 10 days for desulfurization as compared to that of non-induced culture clearly indicating the inducibility of the desulfurization pathway of DMT-7.In addition,Lysinibacillus sphaericus DMT-7 also possess the ability to utilize broad range of substrates as sole source of sulfur such as benzothiophene,3,4-benzo DBT,4,6-dimethyl DBT,and 4,6-dibutyl DBT.Therefore,Lysinibacillus sphaericus DMT-7 could serve as model system for efficient biodesulfurization of diesel and petrol.展开更多
By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, F...By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, FTIR, UVvis,SEM, EDS, and TEM techniques. The test results showed that TiO_2 was amorphous, the TiO_2/BMMS catalyst had an ordered bimodal mesoporous structure, and the chemical interaction existed between BMMS and TiO_2. Since the TiO_2/BMMS had a lower band gap, its photocatalytic activity was better than TiO_2. Under UV irradiation a one-pot PODS system was set up, using TiO_2/BMMS as the catalyst, H_2O_2 as the oxidant, and methanol as the solvent. The TiO_2/BMMS catalyst showed better photocatalytic activity than the mono-modal mesoporous TiO_2/SBA-15 catalyst, and the desulfurization rate of dibenzothiophene(DBT) over TiO_2/BMMS catalyst could reach 99._2%. The TiO_2/BMMS catalyst also had so good stability that the desulfurization rate of DBT did not drop apparently after 8 cycles of reusing, and could still be close to 90%.展开更多
Rhodococcus erythropolis USTB-03 is a promising bacterial strain for the biodesulfurization of dibenzothiophene （DBT） via a sulfurspecific pathway in which DBT is converted to 2-hydroxybiphenyl （2HBP） as an end pr...Rhodococcus erythropolis USTB-03 is a promising bacterial strain for the biodesulfurization of dibenzothiophene （DBT） via a sulfurspecific pathway in which DBT is converted to 2-hydroxybiphenyl （2HBP） as an end product. The effects of nicotinamide and riboflavin on the sulfur specific activity （SA） of DBT biodesulfurization by R. erythropolis USTB-03 were investigated. Both nicotinamide and riboflavin were found to enhance the expression of SA, which was not previously reported. When R. erythropolis USTB-03 was grown on a medium containing nicotinamide of 10.0 mmol or riboflavin of 50.0 μmol, SA was raised from 68.0 or so to more than 130 mmol 2HBP/（kg dry cells.h）. When R. erythropolis USTB-03 was grown in the presence of both nicotinamide of 5.0 mmol and riboflavin of 25.0 μmol, SA was further increased to 159.0 mmol 2HBP/（kg dry cells.h）. It is suggested that the biological synthesis of reduced form of flavin mononucleotide （FMNH2）, an essential coenzyme for the activities of biodesulfurization enzyme Dsz C and A, might be enhanced by nicotinamide and riboflavin, which was responsible for the increased SA of R. erythropolis USTB-03.展开更多
Dibenzothiophene(DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation effi...Dibenzothiophene(DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation efficiencies were clearly improved with increasing C/N ratio in reed wetland sediments, tidal wetlands sediments and estuary wetland sediments. The quantitative response relationships between DBT degradation rates and related functional genes demonstrate that the Kodama pathway-related gene groups were dominant factors at low C/N ratios, while the 4S-related gene groups mainly determined the degradation rate when the C/N ratio was up to 5. Network analysis also shows that the pathway shifts from the Kodama pathway to the 4S pathway occurred through changes in the connections between functional genomes and rates. Furthermore, there were competition and collaboration between the Kodama and 4S pathways. The 4S pathway-related bacteria were more active in estuary wetland sediments compared with reed wetland sediments and tidal wetland sediments. The higher degradation efficiency in estuary wetland sediments may indicate the greater participation of the 4S pathway in the DBT biodegradation reaction. And the effects of ring cleavage of Kodama pathway caused more complete metabolizing of DBT.展开更多
V2O3 nanoparticles with high surface area have been successfully prepared by a new solvothermal method without using any surfactant and template. The size of V2O3 nanoparticles is mostly equal to 10 nm-30 nm. The high...V2O3 nanoparticles with high surface area have been successfully prepared by a new solvothermal method without using any surfactant and template. The size of V2O3 nanoparticles is mostly equal to 10 nm-30 nm. The highest surface area of obtained V2O3 nanoparticles reaches 49 m2/g. Several kinds of V2O3 catalysts were prepared by different methods. All these V2O3 catalysts obtained thereby showed high catalytic activity for oxidative desulfurization(ODS) reaction by using tert-butyl hydroperoxide as the oxidant. The V2O3 catalyst with a highest ODS activity was obtained under the following conditions: The catalyst was prepared upon using V2O5 as the vanadium source, methanol as the solvent, and oxalic acid as the complexing reagent at a V2O5/oxalic acid molar ratio of 1:2. The process for ODS of dibenzothiophene was carried out under mild conditions(under atmospheric pressure and at a relatively low temperature). The highest ODS activity of the obtained V2O3 nanoparticles can be attributed to their highest surface area.展开更多
Sulfur emission through fuel combustion is a global problem because it is a major cause of acid rain. Crud oil contains many heterocyclic organic sulfur compounds, among which dibenzothiophene(DBT) and DBTs bearing al...Sulfur emission through fuel combustion is a global problem because it is a major cause of acid rain. Crud oil contains many heterocyclic organic sulfur compounds, among which dibenzothiophene(DBT) and DBTs bearing alkyl substitutions usually are representative compounds. A strain was isolated from refinery sludge and identified as Corynebacterium ZD-1. The behavior of DBT degradation by ZD-1 in aqueous phase was investigated. Corynebacterium ZD-1 could metabolize DBT to 2-hydroxybiphenyl(2-HBP) as the dead-end metabolite through a sulfur-specific pathway. In shake flask culture, ZD-1 had its maximal desulfurization activity in the late exponential growth phase and the specific production rate of 2-HBP was about 0.14(mmol·kg dry cell -1·min -1, mmol·KDC -1·min -1). Active resting cells for desulfurization should be prepared only in this period. 2-HBP inhibited the growth of strain ZD-1, the production of DBT degradation enzymes, and the activity of enzymes. Sulfate inhibited the production of dibenzothiophene(DBT) degradation enzymes but had no effect on the enzymes' activity. The production rates of 2-HBP at lower cell densities were higher and the maximum amount conversion of DBT to 2-HBP(0.067 mmol/L) after 8 h was gained at 9.2 g dry cell/L rather higher cell density. The results indicated that this newly isolated strain could be a promising biocatalyst for DBT desulfurization.展开更多
A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70 ℃ and modified by loading Ag^+to improve the selective adsorption per...A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70 ℃ and modified by loading Ag^+to improve the selective adsorption performance.The MOF-101 and Ag^+/MOF-101 prepared were characterised by powder X-ray diffraction,X-ray fluo re scence,Fourier trans fo rm infrared spectroscopy,scanning electro n microscopy,and thermogravimetric analysis.The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene(DBT)from model oils.The loading of Ag^+enhanced the deep adsorptive desulfurization capacity fo r DBT and significantly weaken the adsorption competitiveness of toluene.As a result,the DBT concentration of model oil was reduced from 50 ppms to 10.2 ppms.Possible understandings were put forward to explain the adsorption performance of Ag^+/MOF-101.The kinetics and isotherm data can be well-described by the pseudo-second-order kinetic model and the Langmuir model.展开更多
In this research, the degradation of dibenzothiophene(DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology(RSM) based on the Box-Behnken design(BBD...In this research, the degradation of dibenzothiophene(DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology(RSM) based on the Box-Behnken design(BBD) was applied for evaluating the interactive effects of four independent variables including substrate concentration, temperature, pH and agitation rate on the DBT removal response. A total of 29 experiments for four factors at three levels were conducted in present study. A second-order regression model was then developed, and the analysis of variance(ANOVA) illustrated that the proposed quadratic model could be utilized to navigate the design space. The value of determination coefficient(R2=0.953 4) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that DBT removal was more significantly affected(P<0.000 1) by substrate concentration compared with other three parameters. An 100% degradation of DBT could be obtained by Pseudomonas sp. LKY-5 at a substrate concentration of 100 mg/L.展开更多
Supported ionic liquid(IL) catalysts [Cmim]PMoO/Am TiO(amorphous TiO) were synthesized through a one-step method for extraction coupled catalytic oxidative desulfurization(ECODS) system. Characterizations such as FTIR...Supported ionic liquid(IL) catalysts [Cmim]PMoO/Am TiO(amorphous TiO) were synthesized through a one-step method for extraction coupled catalytic oxidative desulfurization(ECODS) system. Characterizations such as FTIR, DRS,wide-angle XRD, Nadsorption–desorption and XPS were applied to analyze the morphology and Keggin structure of the catalysts. In ECODS with hydrogen peroxide as the oxidant, it was found that ILs with longer alkyl chains in the cationic moiety had a better effect on the removal of dibenzothiophene. The desulfurization could reach 100% under optimal conditions, and GC–MS analysis was employed to detect the oxidized product after the reaction. Factors affecting the desulfurization efficiencies were discussed, and a possible mechanism was proposed. In addition, cyclic experiments were also conducted to investigate the recyclability of the supported catalyst. The catalytic activity of [Cmim]PMoO/Am TiOonly dropped from 100% to 92.9% after ten cycles, demonstrating the good recycling performance of the catalyst and its potential industrial application.展开更多
Macroporous 3D carbon doped with nitrogen confined Mo catalyst(MoO_(x)@CN)had been prepared by a facile one-step pyrolysis technique using silica as a template and was employed for oxidative desulfurization(ODS)of dib...Macroporous 3D carbon doped with nitrogen confined Mo catalyst(MoO_(x)@CN)had been prepared by a facile one-step pyrolysis technique using silica as a template and was employed for oxidative desulfurization(ODS)of dibenzothiophene(DBT)in model fuel with H2O_(2) as oxidant.The effect of different ope rating conditions(i.e.,reaction te mperature and time,catalyst dosage,H2O_(2)/DBT(O/S)molar ratio)were also systematic investigated.Under the optimal reaction condition,MoO_(x)@CN catalyst exhibited highly excellent ODS performance toward DBT,the highest sulfur removal efficiency can be up to 99.9%and sulfur content was wiped out from 800 ppm to 10 ppm.Due to the robust 3D structure promoting rapid transfer,in addition to the increased number of active sites induced by the Mo vacancies,the catalyst,prepared using chitosan and ammonium heptamolybdate in a mass ratio of 1:0.5,displayed rapid kinetics and low activation energy in the oxidation of dibenzothiophene.Moreover,it exhibited excellent recyclability after five cycles without any obvious decrease in catalytic activity for the oxidative desulfurization reaction.展开更多
Five bacterial strains, which are able to grow and to disintegratedibenzothiophene (DBT) and diben- zothiophene sulfone (DBTO_2) infossil fuels, are isolated. Analysis of products of DBT metabolizedby these strains sh...Five bacterial strains, which are able to grow and to disintegratedibenzothiophene (DBT) and diben- zothiophene sulfone (DBTO_2) infossil fuels, are isolated. Analysis of products of DBT metabolizedby these strains shows that different bacteria strains oxidized DBTby different pathways. The isolated strains R-6, $-16, $-9 and R-8can metabolize DBT to DBTO_2 and 3-hydroxybiphenyl (HBP), which areidentified as Bacillus brevis, Bacillus Sphaericus, Nocardiagloberula and Pseudomonas delafieldii respectively.展开更多
A series of Al‐containing mesostructured cellular silica foams(Al‐MCFs)with different Si/Al molar ratios(x;x=10,20,30,40,or50)were prepared by a post synthetic method using aluminum isopropoxide as an alumina source...A series of Al‐containing mesostructured cellular silica foams(Al‐MCFs)with different Si/Al molar ratios(x;x=10,20,30,40,or50)were prepared by a post synthetic method using aluminum isopropoxide as an alumina source.The corresponding NiMo catalysts supported on Al‐MCFs were prepared and evaluated using dibenzothiophene(DBT)as the probe reactant.All the synthesized samples were characterized by small‐angle X‐ray scattering,scanning electron microscopy,nitrogen adsorption‐desorption,UV‐Vis diffuse reflectance spectroscopy,H2temperature‐programmed reduction,27Al MAS NMR,temperature‐programmed desorption of ammonia,pyridine‐FTIR,Raman spectroscopy,HRTEM,and X‐ray photoelectron spectroscopy to analyze their physicochemical properties and to gain a deeper insight of the interrelationship between the structures and the catalytic performance.The synthesis mechanism was proposed to involve the formation of Br?nsted acid and Lewis acid sites through the replacement of Si4+with Al3+.Aluminum introduced into MCFs by the post synthetic method has a negligible influence on the mesostructure of the parent MCFs but can form silicoaluminate materials with moderate Br?nsted acidity.For Al‐MCFs(x)materials,the detection of tetrahedrally coordinated Al3+cations demonstrated that the Al species had been successfully incorporated into the silicon frameworks.Furthermore,the DBT hydrodesulfurization(HDS)catalytic activity of the NiMo/Al‐MCFs(x)catalysts increased with increasing Si/Al molar ratio,and reached a maximum at a Si/Al molar ratio of20.The interaction of Ni and Mo species with the support became stronger when Al was incorporated into the MCFs supports.The high activities of the NiMo/Al‐MCFs catalysts for the DBT HDS were attributed to the suitable acidity properties and good dispersions of the Ni and Mo active phases.展开更多
The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） wit...The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.展开更多
Adsorption properties of dibenzothiophene (DBT) on a CNT (carbon nanotube) support as well as on CoMoS/CNT and CoMoO/CNT catalysts have been studied. Consecutive desorption of adsorbates was measured by TGA. The commo...Adsorption properties of dibenzothiophene (DBT) on a CNT (carbon nanotube) support as well as on CoMoS/CNT and CoMoO/CNT catalysts have been studied. Consecutive desorption of adsorbates was measured by TGA. The commonly used carriers AC (activated carbon), γ-Al_2O_3, and their supported catalysts (CoMoO/AC, CoMoS/AC, CoMoO/γ-Al_2O_3, CoMoS/γ-Al_2O_3)were also subjected to analysis for comparison. The acidic properties of the samples were characterized using the NH_3-TPD technique. Correlation between the adsorption of DBT and the acidic properties of the catalysts has been established. It was found that the Co-Mo catalysts in the sulfide state adsorbed much more DBT molecules than the corresponding Co-Mo catalysts in the oxide state. The CoMoS/CNT catalyst exhibited very high HDS activity and selectivity, as compared with the CoMoS/γ-Al)_2O_3 catalysts. Based on the BET data and the high hydrogenolysis/hydrogenation selectivity of the CoMoS/CNT, it was deduced that more than 90% of the DBT molecules adsorbed on the CoMoS/CNT with an end-on mode, and the surface of the CoMoS/CNT catalyst was almost fully covered with DBT molecules. Although the AC support had very high surface area and high loading ability, the AC supported CoMoS catalyst showed lower HDS activity, as compared with the CoMoS/γ-Al_2O_3 catalyst.展开更多
The potential of carrying out oxidative desulfurization(ODS) using oxygen as an oxidant was explored in this work. n-Octane firstly reacted with oxygen to produce hydroperoxides in-situ, which were then used as oxidan...The potential of carrying out oxidative desulfurization(ODS) using oxygen as an oxidant was explored in this work. n-Octane firstly reacted with oxygen to produce hydroperoxides in-situ, which were then used as oxidants to oxidize the dibenzothiophene(DBT) in the absence of catalysts. The hydroperoxides generated in-situ were effective in oxidizing DBT to its corresponding dibenzothiophene sulfone(DBTO_2) which was characterized by FT-IR and ~1H-NMR. The removal rate of DBT could reached 98.4% under conditions covering a temperaure of 140℃, a rection duration of 4 h, and an oxygen partial pressure of 0.4 MPa. The influences of different hydrocarbon components in diesel on DBT removal were investigated. The results showed that cyclohexane and n-dodecane had no effect on the removal of DBT, but xylene had a slight negative effect on DBT removal. A possible oxidation mechanism was proposed and the concentration of hydroperoxides in both O_2-oxidized octane and model diesel were detected.展开更多
The aim of the current work is to synthesize the new heterocyclic pentacyclic condensed systems that combine benzothiophen and benzimidazole/triazole into one molecule. The dibenzothiophene was taken as an initial com...The aim of the current work is to synthesize the new heterocyclic pentacyclic condensed systems that combine benzothiophen and benzimidazole/triazole into one molecule. The dibenzothiophene was taken as an initial compound and by consistent “extension” was annihilated the imidazole and triazole nucleuses. As a result two new pentacyclic systems were produced: 3H-, 7H-diimidazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide and 3H-, 7H-ditriazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide with the promising antimi-crobial activity. Their spectral characteristics were studied.展开更多
基金financially supported by the National Natural Science Foundation of China (NNSFC,21206017)~~
文摘Micro-mesoporous ZK-1 molecular sieves with different Si/Al ratios were used as supports for binary Co-Mo hydrodesulfurization（HDS） catalysts.The CoMo/ZK-1 catalysts were prepared using an over-loading impregnation method,and characterized using N2 physisorption,X-ray diffraction,temperature-programmed NH3 desorption,temperature-programmed reduction（TPR）,ultraviolet-visible diffuse reflectance spectroscopy,and high-resolution transmission electron microscopy（HRTEM）.The results show that the CoMo/ZK-1 catalysts have high surface areas（～700 m^2/g）,large pore volumes,and hierarchical porous structures,which promote the dispersion of Co and Mo oxide phases on the ZK-1 supports.The TPR results show that the interactions between the Co and Mo oxide phases and the ZK-1 support are weaker than those in the CoMo/γ-Al2O3 catalyst.The HRTEM results show that the CoMo/ZK-1 catalysts have better MoS2 dispersion and more active edge sites.The catalysts were tested in HDS of dibenzothiophene.Under mild reaction conditions,the activity of Co and Mo sulfides supported on ZK-1 was higher than those of Co and Mo sulfides supported on ZSM-5,A1KIT-1,and γ-Al2O3.
基金the National Natural Science Foundation of China(No.50273024)the Foundation for the Author of National Excellent Doctoral Dissertation of PR China(FANEDD,No 200333)+1 种基金Natural Foundation of Jiangsu Province(No.BK2003031)the Foundation of Jiangsu Province Education Committee(No.03KJB 150115)for financial support.
文摘Two novel V-shaped symmetric chromophores： E-2,8-bis（4-vinyl-4-carbazol-9-yl）diben- zothiophene （abbreviated as SK-G1） and E-2,8-bis（4-vinyl-4-triphenylamino） dibenzothiophene （abbreviated as ST-G1） have been synthesized and characterized. Their two photon absorption properties were measured by the open-aperture femtosecond Z-scan technique and the nanosecond nonlinear optical transmission （NLT）, respectively, when pumped by Ti： sapphire laser at 750 nm and 800 nm.
基金supported by the Science and Technology Project of Zhejiang Province(2016C33039)the Public Technology Research Project(Analysis and Measurement)of Zhejiang Province(LGC19B070004)+1 种基金State Key Laboratory of Environmental Chemistry and Ecotoxicology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences(KF2018-15)Natural Science Foundation of Zhejiang Province(LY18C030003)
文摘Polychlorinated dibenzothiophenes(PCDTs)and their corresponding sulfone(PCDTO2)compounds are a group of important persistent organic pollutants.In the present study,geometrical optimization and subsequent calculations of electrostatic potentials(ESPs)on molecular surface have been performed for all 135 PCDTs and 135 PCDTO2 congeners at the HF/6-31G*level of theory.A number of statistically-based parameters have been extracted.Linear relationship between gas-chromatographic retention index(RI)and the structural descriptors have been established by multiple linear regression.The result shows that two descriptors derived from positive electrostatic potential on molecular surface,■andπ,together with the molecular volume(Vmc)and the energy of the lowest unoccupied molecular orbital(ELUMO)can be well used to express the quantitative structure-retention relationship(QSRR)of PCDTs and PCDTO2.Predictive capability of the two models has been demonstrated by leave-one-out cross-validation with the cross-validated correlation coefficient(RCV)of 0.996 and 0.997,respectively.Furthermore,the predictive power of the models is further examined for the external test set.Correlation coefficients(R)between the observed and predicted RI values for the external test set are 0.997 and0.998,respectively,validating the robustness and good prediction of our model.The QSRR model established may provide again a powerful method for predicting chromatographic properties of aromatic organosulfur compounds.
基金funded by the National Natural Science Foundation of China (Grant No. 41272158)the State Key Laboratory of Petroleum Resources and Prospecting (PRP/indep-2-1302)
文摘Aromatic fractions of 140 oils and condensates that originated from different types of source rocks （marine shale,terrestrial shale and marine carbonate） were analyzed using gas chromatographymass spectrometry （GC-MS） to investigate the relative distributions of methylated dibenzothiophenes with respect to thermal maturity.The positions of methyl groups of trimethyldibenzothiophene isomers （TMDBTs） including those used in the definition of maturity indicator TMDBT index in previous studies were firmly identified by co-elution of internal standards in GC-MS analysis and by comparing with reported retention indices.A new maturity ratio related to dimethyldibenzothiophenes （DMDBTs） is proposed on the basis of the differences in thermodynamic stability among different DMDBT isomers.Another maturity index （TMDBT-I2） based on TMDBTs is also suggested on the basis of our empirical observations and presumed thermodynamic stability of TMDBT isomers.These two newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratio and TMDBT-I2 correlate well with MDR （4-/1-methyldibenzothiophene）and 2,4-/1,4-DMDBT ratios,suggesting their common chemical reaction mechanisms and similar behavior with increasing maturity.Therefore,they can be effectively applied for maturity assessments.Furthermore,the TMDBTs related maturity parameters are more reliable for over-mature oils and condensates due to the relatively higher concentrations of thermodynamically unstable TMDBT isomers,i.e.1,4,6-,1,4,8-and 3,4,6-TMDBT in this study than those of 1-methyldibenzothiophene （1-MDBT） or 1,4-DMDBT.In contrast with 4,6-/1,4-DMDBT,the newly proposed （2,6 ＋ 3,6）-/1,4-DMDBT ratios for oils that originated from different types of source rocks have approximately same relationship with the oil maturity （Rc %）.This suggests that the lithology and organic facies may have relatively less influence on （2,6 ＋ 3,6）-/1,4-DMDBT ratio compared to 4,6-/1,4-DMDBT.The maturity parameters based on methylated dibenzothiophenes are particularly useful in the maturity assessments of post-and over-mature oils and condensates and can complement maturity indicators based on steranes and terpanes.
文摘A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene（DBT） was isolated from diesel contaminated soil.The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7（NCBI GenBank Accession No.GQ496620） using 16S rDNA gene sequence analysis.The desulfurized product of DBT,2-hydroxybiphenyl（2HBP）,was identified and confirmed by high performance liquid chromatography analysis and gas chromatography-mass spectroscopy analysis respectively.The desulfurization kinetics revealed that DMT-7 started desulfurization of DBT into 2HBP after the lag phase of 24 hr,exponentially increasing the accumulation of 2HBP up to 15 days leading to approximately 60% desulfurization of the DBT.However,further growth resulted into DBT degradation.The induced culture of DMT-7 showed shorter lag phase of 6 hr and early onset of stationary phase within 10 days for desulfurization as compared to that of non-induced culture clearly indicating the inducibility of the desulfurization pathway of DMT-7.In addition,Lysinibacillus sphaericus DMT-7 also possess the ability to utilize broad range of substrates as sole source of sulfur such as benzothiophene,3,4-benzo DBT,4,6-dimethyl DBT,and 4,6-dibutyl DBT.Therefore,Lysinibacillus sphaericus DMT-7 could serve as model system for efficient biodesulfurization of diesel and petrol.
基金financially supported by the Program for Liaoning Excellent Talents in University,abbreviated as“LNET”(LJQ2015062)Program for Science and Technology Agency of Liaoning Province(20170540585)+1 种基金General Scientific Research Project of Liaoning Provincial Department of Education(L2015296,L2016018)Science and Technology Planning project of Fushun(FSKJHT201376)
文摘By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, FTIR, UVvis,SEM, EDS, and TEM techniques. The test results showed that TiO_2 was amorphous, the TiO_2/BMMS catalyst had an ordered bimodal mesoporous structure, and the chemical interaction existed between BMMS and TiO_2. Since the TiO_2/BMMS had a lower band gap, its photocatalytic activity was better than TiO_2. Under UV irradiation a one-pot PODS system was set up, using TiO_2/BMMS as the catalyst, H_2O_2 as the oxidant, and methanol as the solvent. The TiO_2/BMMS catalyst showed better photocatalytic activity than the mono-modal mesoporous TiO_2/SBA-15 catalyst, and the desulfurization rate of dibenzothiophene(DBT) over TiO_2/BMMS catalyst could reach 99._2%. The TiO_2/BMMS catalyst also had so good stability that the desulfurization rate of DBT did not drop apparently after 8 cycles of reusing, and could still be close to 90%.
文摘Rhodococcus erythropolis USTB-03 is a promising bacterial strain for the biodesulfurization of dibenzothiophene （DBT） via a sulfurspecific pathway in which DBT is converted to 2-hydroxybiphenyl （2HBP） as an end product. The effects of nicotinamide and riboflavin on the sulfur specific activity （SA） of DBT biodesulfurization by R. erythropolis USTB-03 were investigated. Both nicotinamide and riboflavin were found to enhance the expression of SA, which was not previously reported. When R. erythropolis USTB-03 was grown on a medium containing nicotinamide of 10.0 mmol or riboflavin of 50.0 μmol, SA was raised from 68.0 or so to more than 130 mmol 2HBP/（kg dry cells.h）. When R. erythropolis USTB-03 was grown in the presence of both nicotinamide of 5.0 mmol and riboflavin of 25.0 μmol, SA was further increased to 159.0 mmol 2HBP/（kg dry cells.h）. It is suggested that the biological synthesis of reduced form of flavin mononucleotide （FMNH2）, an essential coenzyme for the activities of biodesulfurization enzyme Dsz C and A, might be enhanced by nicotinamide and riboflavin, which was responsible for the increased SA of R. erythropolis USTB-03.
基金Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No.51721006)the National Natural Science Foundation of China (No.51679001) provided support for this study
文摘Dibenzothiophene(DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation efficiencies were clearly improved with increasing C/N ratio in reed wetland sediments, tidal wetlands sediments and estuary wetland sediments. The quantitative response relationships between DBT degradation rates and related functional genes demonstrate that the Kodama pathway-related gene groups were dominant factors at low C/N ratios, while the 4S-related gene groups mainly determined the degradation rate when the C/N ratio was up to 5. Network analysis also shows that the pathway shifts from the Kodama pathway to the 4S pathway occurred through changes in the connections between functional genomes and rates. Furthermore, there were competition and collaboration between the Kodama and 4S pathways. The 4S pathway-related bacteria were more active in estuary wetland sediments compared with reed wetland sediments and tidal wetland sediments. The higher degradation efficiency in estuary wetland sediments may indicate the greater participation of the 4S pathway in the DBT biodegradation reaction. And the effects of ring cleavage of Kodama pathway caused more complete metabolizing of DBT.
基金supported by the National Nature Science Foundation of China (21303088)
文摘V2O3 nanoparticles with high surface area have been successfully prepared by a new solvothermal method without using any surfactant and template. The size of V2O3 nanoparticles is mostly equal to 10 nm-30 nm. The highest surface area of obtained V2O3 nanoparticles reaches 49 m2/g. Several kinds of V2O3 catalysts were prepared by different methods. All these V2O3 catalysts obtained thereby showed high catalytic activity for oxidative desulfurization(ODS) reaction by using tert-butyl hydroperoxide as the oxidant. The V2O3 catalyst with a highest ODS activity was obtained under the following conditions: The catalyst was prepared upon using V2O5 as the vanadium source, methanol as the solvent, and oxalic acid as the complexing reagent at a V2O5/oxalic acid molar ratio of 1:2. The process for ODS of dibenzothiophene was carried out under mild conditions(under atmospheric pressure and at a relatively low temperature). The highest ODS activity of the obtained V2O3 nanoparticles can be attributed to their highest surface area.
文摘Sulfur emission through fuel combustion is a global problem because it is a major cause of acid rain. Crud oil contains many heterocyclic organic sulfur compounds, among which dibenzothiophene(DBT) and DBTs bearing alkyl substitutions usually are representative compounds. A strain was isolated from refinery sludge and identified as Corynebacterium ZD-1. The behavior of DBT degradation by ZD-1 in aqueous phase was investigated. Corynebacterium ZD-1 could metabolize DBT to 2-hydroxybiphenyl(2-HBP) as the dead-end metabolite through a sulfur-specific pathway. In shake flask culture, ZD-1 had its maximal desulfurization activity in the late exponential growth phase and the specific production rate of 2-HBP was about 0.14(mmol·kg dry cell -1·min -1, mmol·KDC -1·min -1). Active resting cells for desulfurization should be prepared only in this period. 2-HBP inhibited the growth of strain ZD-1, the production of DBT degradation enzymes, and the activity of enzymes. Sulfate inhibited the production of dibenzothiophene(DBT) degradation enzymes but had no effect on the enzymes' activity. The production rates of 2-HBP at lower cell densities were higher and the maximum amount conversion of DBT to 2-HBP(0.067 mmol/L) after 8 h was gained at 9.2 g dry cell/L rather higher cell density. The results indicated that this newly isolated strain could be a promising biocatalyst for DBT desulfurization.
文摘A copper-centred metal-organic framework material MOF-101 with 2-bromine terephthalic acid as ligands was synthesized by solvothermal method at 70 ℃ and modified by loading Ag^+to improve the selective adsorption performance.The MOF-101 and Ag^+/MOF-101 prepared were characterised by powder X-ray diffraction,X-ray fluo re scence,Fourier trans fo rm infrared spectroscopy,scanning electro n microscopy,and thermogravimetric analysis.The adsorptive desulphurisation was quantified by adsorbing dibenzothiophene(DBT)from model oils.The loading of Ag^+enhanced the deep adsorptive desulfurization capacity fo r DBT and significantly weaken the adsorption competitiveness of toluene.As a result,the DBT concentration of model oil was reduced from 50 ppms to 10.2 ppms.Possible understandings were put forward to explain the adsorption performance of Ag^+/MOF-101.The kinetics and isotherm data can be well-described by the pseudo-second-order kinetic model and the Langmuir model.
基金support provided by the Fundamental Research Funds for the Central Universities (No. 12CX06043A) of Chinathe Key Laboratory of Marine Spill Oil Identification and Damage Assessment Technology,SOA(No. 201407)
文摘In this research, the degradation of dibenzothiophene(DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology(RSM) based on the Box-Behnken design(BBD) was applied for evaluating the interactive effects of four independent variables including substrate concentration, temperature, pH and agitation rate on the DBT removal response. A total of 29 experiments for four factors at three levels were conducted in present study. A second-order regression model was then developed, and the analysis of variance(ANOVA) illustrated that the proposed quadratic model could be utilized to navigate the design space. The value of determination coefficient(R2=0.953 4) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that DBT removal was more significantly affected(P<0.000 1) by substrate concentration compared with other three parameters. An 100% degradation of DBT could be obtained by Pseudomonas sp. LKY-5 at a substrate concentration of 100 mg/L.
基金financially supported by the National Natural Science Foundation of China (Nos. 21576122, 21646001, 21506080)Natural Science Foundation of Jiangsu Province (Nos. BK20150485, BK20170528)+2 种基金China Postdoctoral Science Foundation (2017M611727)Jiangsu Planned Projects for Postdoctoral Research Funds (1701104B)supported by the Student Innovation and Entrepreneurship Training Program (201810299332 W)
文摘Supported ionic liquid(IL) catalysts [Cmim]PMoO/Am TiO(amorphous TiO) were synthesized through a one-step method for extraction coupled catalytic oxidative desulfurization(ECODS) system. Characterizations such as FTIR, DRS,wide-angle XRD, Nadsorption–desorption and XPS were applied to analyze the morphology and Keggin structure of the catalysts. In ECODS with hydrogen peroxide as the oxidant, it was found that ILs with longer alkyl chains in the cationic moiety had a better effect on the removal of dibenzothiophene. The desulfurization could reach 100% under optimal conditions, and GC–MS analysis was employed to detect the oxidized product after the reaction. Factors affecting the desulfurization efficiencies were discussed, and a possible mechanism was proposed. In addition, cyclic experiments were also conducted to investigate the recyclability of the supported catalyst. The catalytic activity of [Cmim]PMoO/Am TiOonly dropped from 100% to 92.9% after ten cycles, demonstrating the good recycling performance of the catalyst and its potential industrial application.
基金the Applied Basic Research Project of Science and Technology Department of Sichuan Province(No.2020YJ0418)。
文摘Macroporous 3D carbon doped with nitrogen confined Mo catalyst(MoO_(x)@CN)had been prepared by a facile one-step pyrolysis technique using silica as a template and was employed for oxidative desulfurization(ODS)of dibenzothiophene(DBT)in model fuel with H2O_(2) as oxidant.The effect of different ope rating conditions(i.e.,reaction te mperature and time,catalyst dosage,H2O_(2)/DBT(O/S)molar ratio)were also systematic investigated.Under the optimal reaction condition,MoO_(x)@CN catalyst exhibited highly excellent ODS performance toward DBT,the highest sulfur removal efficiency can be up to 99.9%and sulfur content was wiped out from 800 ppm to 10 ppm.Due to the robust 3D structure promoting rapid transfer,in addition to the increased number of active sites induced by the Mo vacancies,the catalyst,prepared using chitosan and ammonium heptamolybdate in a mass ratio of 1:0.5,displayed rapid kinetics and low activation energy in the oxidation of dibenzothiophene.Moreover,it exhibited excellent recyclability after five cycles without any obvious decrease in catalytic activity for the oxidative desulfurization reaction.
基金Supported by the special funds for major state basic research project (No.G2000048004) and SINOPEC.
文摘Five bacterial strains, which are able to grow and to disintegratedibenzothiophene (DBT) and diben- zothiophene sulfone (DBTO_2) infossil fuels, are isolated. Analysis of products of DBT metabolizedby these strains shows that different bacteria strains oxidized DBTby different pathways. The isolated strains R-6, $-16, $-9 and R-8can metabolize DBT to DBTO_2 and 3-hydroxybiphenyl (HBP), which areidentified as Bacillus brevis, Bacillus Sphaericus, Nocardiagloberula and Pseudomonas delafieldii respectively.
基金supported by National Natural Science Foundation of China (21276277,U1463207)CNOOC Project+1 种基金CNPC major projectthe Opening Project of Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology (2015K003)~~
文摘A series of Al‐containing mesostructured cellular silica foams(Al‐MCFs)with different Si/Al molar ratios(x;x=10,20,30,40,or50)were prepared by a post synthetic method using aluminum isopropoxide as an alumina source.The corresponding NiMo catalysts supported on Al‐MCFs were prepared and evaluated using dibenzothiophene(DBT)as the probe reactant.All the synthesized samples were characterized by small‐angle X‐ray scattering,scanning electron microscopy,nitrogen adsorption‐desorption,UV‐Vis diffuse reflectance spectroscopy,H2temperature‐programmed reduction,27Al MAS NMR,temperature‐programmed desorption of ammonia,pyridine‐FTIR,Raman spectroscopy,HRTEM,and X‐ray photoelectron spectroscopy to analyze their physicochemical properties and to gain a deeper insight of the interrelationship between the structures and the catalytic performance.The synthesis mechanism was proposed to involve the formation of Br?nsted acid and Lewis acid sites through the replacement of Si4+with Al3+.Aluminum introduced into MCFs by the post synthetic method has a negligible influence on the mesostructure of the parent MCFs but can form silicoaluminate materials with moderate Br?nsted acidity.For Al‐MCFs(x)materials,the detection of tetrahedrally coordinated Al3+cations demonstrated that the Al species had been successfully incorporated into the silicon frameworks.Furthermore,the DBT hydrodesulfurization(HDS)catalytic activity of the NiMo/Al‐MCFs(x)catalysts increased with increasing Si/Al molar ratio,and reached a maximum at a Si/Al molar ratio of20.The interaction of Ni and Mo species with the support became stronger when Al was incorporated into the MCFs supports.The high activities of the NiMo/Al‐MCFs catalysts for the DBT HDS were attributed to the suitable acidity properties and good dispersions of the Ni and Mo active phases.
基金Supported by the National Natural Science Foundation of China （20737001）.
文摘The thermodynamic properties of 135 polybrominated dibenzothiophenes （PBDTs） in the gaseous state at 298.15 K and 1.013×10^5 Pa, are calculated using the density functional theory （the B3LYP/6-311G^＊＊） with Gaussian 03. Based on these data, the isodesmic reacflons are designed to calculate the standard enthalpy of formation （△fH^θ） and the standard Gibbs energy of formation （△fG^θ） of PBDTs. The relations of these thermodynamic parameters with the number and positionof bromine subsfituents （NPBS） are discussed, and it is found that there exist good correlations between othermody namic parameters （including heat capacity at constant volume, entropy, enthaipy, free energy, △fH^θ, △fG^θ） and NPBS. Thoe relative stability order of PBDT congeners is proposed theoretically based on the relative magnitude of their △fG^θ. In addition, the values of molar heat capacities at constant pressure （Cp,m） for PBDT c ongelaers are calculated.
文摘Adsorption properties of dibenzothiophene (DBT) on a CNT (carbon nanotube) support as well as on CoMoS/CNT and CoMoO/CNT catalysts have been studied. Consecutive desorption of adsorbates was measured by TGA. The commonly used carriers AC (activated carbon), γ-Al_2O_3, and their supported catalysts (CoMoO/AC, CoMoS/AC, CoMoO/γ-Al_2O_3, CoMoS/γ-Al_2O_3)were also subjected to analysis for comparison. The acidic properties of the samples were characterized using the NH_3-TPD technique. Correlation between the adsorption of DBT and the acidic properties of the catalysts has been established. It was found that the Co-Mo catalysts in the sulfide state adsorbed much more DBT molecules than the corresponding Co-Mo catalysts in the oxide state. The CoMoS/CNT catalyst exhibited very high HDS activity and selectivity, as compared with the CoMoS/γ-Al)_2O_3 catalysts. Based on the BET data and the high hydrogenolysis/hydrogenation selectivity of the CoMoS/CNT, it was deduced that more than 90% of the DBT molecules adsorbed on the CoMoS/CNT with an end-on mode, and the surface of the CoMoS/CNT catalyst was almost fully covered with DBT molecules. Although the AC support had very high surface area and high loading ability, the AC supported CoMoS catalyst showed lower HDS activity, as compared with the CoMoS/γ-Al_2O_3 catalyst.
基金the Undergraduate Innovation and Entrepreneurship Training Project (201710057009) for providing funding and support for this research
文摘The potential of carrying out oxidative desulfurization(ODS) using oxygen as an oxidant was explored in this work. n-Octane firstly reacted with oxygen to produce hydroperoxides in-situ, which were then used as oxidants to oxidize the dibenzothiophene(DBT) in the absence of catalysts. The hydroperoxides generated in-situ were effective in oxidizing DBT to its corresponding dibenzothiophene sulfone(DBTO_2) which was characterized by FT-IR and ~1H-NMR. The removal rate of DBT could reached 98.4% under conditions covering a temperaure of 140℃, a rection duration of 4 h, and an oxygen partial pressure of 0.4 MPa. The influences of different hydrocarbon components in diesel on DBT removal were investigated. The results showed that cyclohexane and n-dodecane had no effect on the removal of DBT, but xylene had a slight negative effect on DBT removal. A possible oxidation mechanism was proposed and the concentration of hydroperoxides in both O_2-oxidized octane and model diesel were detected.
文摘The aim of the current work is to synthesize the new heterocyclic pentacyclic condensed systems that combine benzothiophen and benzimidazole/triazole into one molecule. The dibenzothiophene was taken as an initial compound and by consistent “extension” was annihilated the imidazole and triazole nucleuses. As a result two new pentacyclic systems were produced: 3H-, 7H-diimidazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide and 3H-, 7H-ditriazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide with the promising antimi-crobial activity. Their spectral characteristics were studied.
