A few-layered hexagonal boron nitride nanosheets stabilized platinum nanoparticles(Pt/h-BNNS)is engineered for oxidation-promoted adsorptive desulfurization(OPADS)of fuel oil.It was found that the few-layered structur...A few-layered hexagonal boron nitride nanosheets stabilized platinum nanoparticles(Pt/h-BNNS)is engineered for oxidation-promoted adsorptive desulfurization(OPADS)of fuel oil.It was found that the few-layered structure and the defective sites of h-BNNS not only are beneficial to the stabilization of Pt NPs but also favor the adsorption of aromatic sulfides.By employing Pt/h-BNNS with a Pt loading amount of 1.19 wt%as the active adsorbent and air as an oxidant,a 98.0%sulfur removal over dibenzothiophene(DBT)is achieved along with a total conversion of the DBT to the corresponding sulfones(DBTO_(2)).Detailed experiments show that the excellent desulfurization activity originates from the few-layered structure of h-BNNS and the high catalytic activity of Pt NPs.In addition,the OPADS system with Pt/h-BNNS as the active adsorbent shows remarkable stability in desulfurization performance with the existence of different interferents such as olefin,and aromatic hydrocarbons.Besides,the Pt/h-BNNS can be recycled 12 times without a significant decrease in desulfurization performance.Also,a process flow diagram is proposed for deep desulfurization of fuel oil and recovery of high value-added products,which would promote the industrial application of such OPADS strategy.展开更多
Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic fram...Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.展开更多
A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80 °C to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs w...A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80 °C to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs were characterized byFourier transform infrared spectrophotometry (FT-IR), thermogravimetry/differential thermogravimetry (TG/DTG), andelectron spray ionization mass spectrometry (ESI-MS). The DESs were used as both extractants and catalysts to removedibenzothiophene from fuels via oxidative desulfurization (ODS). Experiments were performed to investigated the influenceof factors such as composition of DES, temperature, oxidant dosage (molar ratio of O:S), DES dosage (volume ratio ofDES:oil), and number of cycles on desulfurization rate. The results indicated that the removal rate of dibenzothiophene (DBT)was affected by the Lewis acidic DESs, with that of H_(3)PO_(4)/0.25∙ZnCl_(2) reaching 96.4% under optimal conditions (Voil=5 mL,VDES=1 mL, an oxidant dosage of 6, T=50 ℃). After six cycles, the desulfurization rate of H_(3)PO_(4)/0.25∙ZnCl_(2) remained above94.1%. The apparent activation energy of dibenzothiophene (DBT) removal reaction was determined by a pseudo-first orderkinetic equation according to the Arrhenius equation to be 32.34 kJ/mol, as estimated. A reaction mechanism is proposedbased on the experimental data and characterization results.展开更多
The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be ...The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be the most promising technology.The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task.In this paper,pentamethylene hexamine(PEHA)and phosphotungstic acid(HPW)were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil.The composite material exhibited excellent catalytic activity and high recyclability,which could reach a 100% dibenzothiophene(DBT)removal rate in 30 min and be recycled at least 5 times.Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW.It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role.This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts.展开更多
The exploration of highly efficient catalysts based on nano-sized Ti-rich titanosilicate zeolites with controllable active titanium species is of great importance in zeolite catalytic reactions.Herein,we reported an e...The exploration of highly efficient catalysts based on nano-sized Ti-rich titanosilicate zeolites with controllable active titanium species is of great importance in zeolite catalytic reactions.Herein,we reported an efficient and facile synthesis of nano-sized Ti-rich TS-1(MFI)zeolites by replacing tetrabutyl orthotitanate(TBOT)with tetrabutyl orthotitanate tetramer(TBOT-tetramer)as the titanium source.The introduced TBOT-tetramer slowed down the zeolite crystallization process,and accordingly balanced the rate of incorporating Ti and the crystal growth and inhibited the massive formation of anatase species.Notably,the prepared Ti-rich TS-1 zeolite sample had a Si/Ti as low as 27.6 in contrast to conventional one with a molar ratio of 40.The TBOT-tetramer endowed the titanosilicate zeolites with enriched active titanium species and enlarged external surface area.It also impeded the formation of anatase species,resulting in superior catalytic behavior toward the oxidative desulfurization of dibenzothiophene compared with the conventional TS-1 zeolite counterpart prepared with TBOT.展开更多
Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performanc...Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performance.Successful encapsulation of phosphotungstic acid(HPW)and ionic liquid(BMImBr)inside the mesoporous cages of MIL-101(Cr)was accomplished through a combination of“bottle around ship”and“ship in bottle”methods.The obtained BMImPW@MIL-101(Cr)composite was characterized by XRD,FTIR,BET,SEM,XPS and ICP methods.Results indicated that the BMImPW@MIL-101(Cr)composites with PW^(3−) loading of 23.1–50.7 wt%were obtained,demonstrating that the“bottle around ship”method is beneficial to make full use of nanocages of MIL-101(Cr)to obtain expected high loading of active PW^(3−) .The BMImPW@MIL-101(Cr)exhibits excellent reusability with no evidence of leaching of active PW^(3−) and BMIm^(+),and well-preserved structure after successive cycles of regeneration and reuse.The significantly improved stability of BMImPW@MIL-101(Cr)as compared to HPW@MIL-101(Cr)is possibly because the leaching of the active PW^(3−) −sites can be greatly suppressed by forming large size of BMImPW owing to introduction of BMIm^(+)cation.The BMImPW@MIL-101(Cr)exhibited excellent catalytic activity for solvent free oxidative desulfurization of refractory sulfides.The enhanced oxidative desulfurization activity as compared to HPW@MIL-101(Cr)can be explained by the intimate contact of sulfides with active PW^(3−) sites owing the strong attraction of BMIm^(+)cation with the sulfides.展开更多
Y-Modified USY was prepared by ion exchange of USY slurry with 0.01 mol·L-1 Y(NO3)3. Phosphotungstic acid (HPW) catalyst supported on USY and Y-USY was prepared by an impregnation method. The materials were chara...Y-Modified USY was prepared by ion exchange of USY slurry with 0.01 mol·L-1 Y(NO3)3. Phosphotungstic acid (HPW) catalyst supported on USY and Y-USY was prepared by an impregnation method. The materials were characterized by NH3-TPD, XRD, and N2 adsorption. The activity for the removal of thiophene was examined in a three-necked flask. The sulfur content of model compound was tested on WK-2D microcoulometric detector. The effect of yttrium and HPW content, reaction temperature and catalysts, activation temperature on the activity of catalysts were investigated. It was shown that the oxidation activity of thiophene decreased with the increase of Y content except for the catalyst of Y 5%. HPW content had limit influence on activity of catalysts. The optimal reaction temperature and activation temperature were 40 and 320 ℃, respectively.展开更多
In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer o...In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.展开更多
By combining the photochemical reaction and liquid–liquid extraction(PODS), we studied desulfurization of model fuel and FCC gasoline. The effects of air flow, illumination time, extractants, volume ratios of extract...By combining the photochemical reaction and liquid–liquid extraction(PODS), we studied desulfurization of model fuel and FCC gasoline. The effects of air flow, illumination time, extractants, volume ratios of extractant/fuel, and catalyst amounts on the desulfurization process of PODS were analyzed in detail. Under the conditions with the air as oxidant(150 ml·min^(-1)), the mixture of DMF–water as extractant(the volume ratio of extractant/oil of 0.5) and photo-irradiation time of 2 h, the sulfur removal rate reached only 42.63% and 39.54% for the model and FCC gasoline, respectively. Under the same conditions, the sulfur removal rate increased significantly up to79% for gasoline in the presence of Cu_2O catalyst(2 g·L^(-1)). The results suggest that the PODS combined with a Cu_2O catalyst seems to be a promising alternative for sulfur removal of gasoline.展开更多
The plasma oxidation desulfurization of thiophene in the liquid phase was studied. Under optimum conditions, the degree of desulfurization and selectivity of the solid sulfide formation can be achieved up to 79% and 4...The plasma oxidation desulfurization of thiophene in the liquid phase was studied. Under optimum conditions, the degree of desulfurization and selectivity of the solid sulfide formation can be achieved up to 79% and 47% respectively.展开更多
A few factors affecting plasma oxidation desulfurization of ethyl- thioether were investigated.Under the typical conditions,the conversion and degree of desulfurization of ethyl-thioether can be achieved up to 88% and...A few factors affecting plasma oxidation desulfurization of ethyl- thioether were investigated.Under the typical conditions,the conversion and degree of desulfurization of ethyl-thioether can be achieved up to 88% and 79% respectively.展开更多
A few factors affecting plasma oxidation desulfurization of isobutyl mercaptan were investigated. Under the reasonable condition, the conversion and degree of desulfurization of isobutyl mercaptan can be achieved up t...A few factors affecting plasma oxidation desulfurization of isobutyl mercaptan were investigated. Under the reasonable condition, the conversion and degree of desulfurization of isobutyl mercaptan can be achieved up to over 95% and 94% respectively.展开更多
12-Tungstophosphoric acid(PW) supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization(ODS) of mixed thiophenic compounds in model oil and crude oil under mild conditions u...12-Tungstophosphoric acid(PW) supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization(ODS) of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide(H2O2) as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-tosulfur compounds(S-compounds) molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene(DBT) and mixed thiophenic model oil under atmospheric pressure at 75 ℃ in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.展开更多
A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo(VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxi...A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo(VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxidative desulfurization(ODS) process. The effect of hydrothermal temperature and crystallization temperature on ODS activity was investigated. The ODS activity of supported MoO2 catalysts with various MoO2 contents were also investigated. The mechanism for formation of MoO2 involving oxalic acid was proposed.展开更多
Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot m...Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government’s standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry.The oxidative desulfurization results showed that benzothiophene(BT) could be completely removed by employing a [(CH)P(CH)]PMoO, DES(ChCl/2 Ac) and HOsystem. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and HO/S(O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene(DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(CH)P(CH)]PMoOwas stable during the reaction process and the oxidative product was dibenzothiophene sulfone(DBTO). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.展开更多
A serial of ordered meso-macroporous phosphotungstic acid(HPW) supported on SiO2 nanocomposites were successfully prepared by a homogeneous precipitation method, using monodispersed polystyrene(PS) microspheres and ca...A serial of ordered meso-macroporous phosphotungstic acid(HPW) supported on SiO2 nanocomposites were successfully prepared by a homogeneous precipitation method, using monodispersed polystyrene(PS) microspheres and cationic surfactant as structure directing agent. These nanocomposites were used as catalysts for oxidative desulfurization(ODS) of model fuel. The materials were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), N2 adsorption-desorption isothrem, X-ray diffraction(XRD), and Fourier transform infrared spectra(FTIR). The characterization results suggested that the as-prepared material possessed ordered meso-macroporous architectures with Keggin type phosphotungstic acid dispersed homogeneously in SiO2 matrix. Under the selected reaction conditions, dibenzothiophene(DBT) in model fuel can be removed within 2 h at room temperature(30 ℃). In addition, only 1.2% of efficiency lose than the fresh catalyst even after 5 cycles.展开更多
A series of mesoporous phosphotungstic acid/alumina composites (HPW/Al_2O_3) with various HPW contents were synthesized by evaporation-induced self-assembly method. These composites were characterized by nitrogen ad...A series of mesoporous phosphotungstic acid/alumina composites (HPW/Al_2O_3) with various HPW contents were synthesized by evaporation-induced self-assembly method. These composites were characterized by nitrogen adsorption-desorption, TEM, FTIR, and UV-vis, and were tested as catalysts in oxidation desulfurization of model fuel composed of dibenzothiophene (DBT) and hydrocarbon, using H202 as the oxidant. These composites exhibited high activity in catalytic oxidation of DBT in model fuel and good reusing ability. The best performance was achieved by using the mesoporous HPW/Al_2O_3 with 15wt% HPW content, which resulted in a DBT conversion of 98% after 2 h reaction at 343 K, and it did not show significant activity degradation after 3 recycles. Characterization results showed that the mesoporous structure of alumina and the Keggin structure of HPW were preserved in the formed composite. These results suggested that HPW/ Al_2O_3 could be a promising catalyst in oxidative desulfurization process.展开更多
The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scann...The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scanning electron microscopy(SEM), infrared spectrometry(IR) and the Brunner-Emmet-Teller(BET) techniques. The WO_3/C composite, in comparison with the WO_3 and C_3N_4, features smaller particle size, bigger surface area and higher desulphurization performance. The influence of the reaction temperature, the catalyst dosage, the reaction time, the oxidant dosage, the sulfide type and the extractant dose on desulfurization reaction was studied. The results showed that the WO_3/C composite revealed a higher desulfurization activity than the WO_3. The desulfurization rate could reach up to 95.8% under optimal conditions covering a catalyst dosage of 0.02 g, a H_2O_2 amount of 0.2 mL, a 1-ethyl-3-methylimidazolium ethyl sulfate(EMIES) amount of 1.0 mL, a reaction temperature of 70 ℃ and a reaction time of 180 min. After five recycles, the desulfurization activity of catalyst did not significantly decline.展开更多
In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammoniu...In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–guest inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.展开更多
With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of variou...With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman,UV–Vis, wide-angle XRD and N2adsorption–desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions.The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone.展开更多
基金financial support from the National Natural Science Foundation of China(22178154,22008094,21908082,21878133)Natural Science Foundation of Jiangsu Province(BK20190852,BK20190854)Natural Science Foundation for Jiangsu Colleges and Universities(19KJB530005).
文摘A few-layered hexagonal boron nitride nanosheets stabilized platinum nanoparticles(Pt/h-BNNS)is engineered for oxidation-promoted adsorptive desulfurization(OPADS)of fuel oil.It was found that the few-layered structure and the defective sites of h-BNNS not only are beneficial to the stabilization of Pt NPs but also favor the adsorption of aromatic sulfides.By employing Pt/h-BNNS with a Pt loading amount of 1.19 wt%as the active adsorbent and air as an oxidant,a 98.0%sulfur removal over dibenzothiophene(DBT)is achieved along with a total conversion of the DBT to the corresponding sulfones(DBTO_(2)).Detailed experiments show that the excellent desulfurization activity originates from the few-layered structure of h-BNNS and the high catalytic activity of Pt NPs.In addition,the OPADS system with Pt/h-BNNS as the active adsorbent shows remarkable stability in desulfurization performance with the existence of different interferents such as olefin,and aromatic hydrocarbons.Besides,the Pt/h-BNNS can be recycled 12 times without a significant decrease in desulfurization performance.Also,a process flow diagram is proposed for deep desulfurization of fuel oil and recovery of high value-added products,which would promote the industrial application of such OPADS strategy.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21978119,22202088)Key Research and Development Plan of Hainan Province(ZDYF2022SHFZ285)Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB636)。
文摘Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.
基金the College Student Innovation and Entrepreneurship Training Program Project of Liaoning Province(202310148016)Doctoral Fund of Liaoning Province(201501105).
文摘A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80 °C to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs were characterized byFourier transform infrared spectrophotometry (FT-IR), thermogravimetry/differential thermogravimetry (TG/DTG), andelectron spray ionization mass spectrometry (ESI-MS). The DESs were used as both extractants and catalysts to removedibenzothiophene from fuels via oxidative desulfurization (ODS). Experiments were performed to investigated the influenceof factors such as composition of DES, temperature, oxidant dosage (molar ratio of O:S), DES dosage (volume ratio ofDES:oil), and number of cycles on desulfurization rate. The results indicated that the removal rate of dibenzothiophene (DBT)was affected by the Lewis acidic DESs, with that of H_(3)PO_(4)/0.25∙ZnCl_(2) reaching 96.4% under optimal conditions (Voil=5 mL,VDES=1 mL, an oxidant dosage of 6, T=50 ℃). After six cycles, the desulfurization rate of H_(3)PO_(4)/0.25∙ZnCl_(2) remained above94.1%. The apparent activation energy of dibenzothiophene (DBT) removal reaction was determined by a pseudo-first orderkinetic equation according to the Arrhenius equation to be 32.34 kJ/mol, as estimated. A reaction mechanism is proposedbased on the experimental data and characterization results.
基金supported by the National Natural Science Foundation of China(22378065,22278077)the Fujian Province Department of Science&Technology,China(2019YZ017001)。
文摘The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be the most promising technology.The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task.In this paper,pentamethylene hexamine(PEHA)and phosphotungstic acid(HPW)were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil.The composite material exhibited excellent catalytic activity and high recyclability,which could reach a 100% dibenzothiophene(DBT)removal rate in 30 min and be recycled at least 5 times.Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW.It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role.This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts.
基金the National Natural Science Foundation of China, China (Grant 21920102005, 22288101, and 21835002)the 111 Project, China (B17020)+2 种基金the European Union through the European Research Council, European Union (grant ERC-AdG-2014-671093, SynCatMatch)the Spanish Government through “Severo Ochoa”, Spain (SEV2016-0683, MINECO) for supporting this workthe financial support from China Scholarship Council, China
文摘The exploration of highly efficient catalysts based on nano-sized Ti-rich titanosilicate zeolites with controllable active titanium species is of great importance in zeolite catalytic reactions.Herein,we reported an efficient and facile synthesis of nano-sized Ti-rich TS-1(MFI)zeolites by replacing tetrabutyl orthotitanate(TBOT)with tetrabutyl orthotitanate tetramer(TBOT-tetramer)as the titanium source.The introduced TBOT-tetramer slowed down the zeolite crystallization process,and accordingly balanced the rate of incorporating Ti and the crystal growth and inhibited the massive formation of anatase species.Notably,the prepared Ti-rich TS-1 zeolite sample had a Si/Ti as low as 27.6 in contrast to conventional one with a molar ratio of 40.The TBOT-tetramer endowed the titanosilicate zeolites with enriched active titanium species and enlarged external surface area.It also impeded the formation of anatase species,resulting in superior catalytic behavior toward the oxidative desulfurization of dibenzothiophene compared with the conventional TS-1 zeolite counterpart prepared with TBOT.
文摘Oxidative desulfurization from fuel oil is one of the important methods for deep desulfurization.The development of efficient oxidative desulfurization catalysts is crucial for improving the desulfurization performance.Successful encapsulation of phosphotungstic acid(HPW)and ionic liquid(BMImBr)inside the mesoporous cages of MIL-101(Cr)was accomplished through a combination of“bottle around ship”and“ship in bottle”methods.The obtained BMImPW@MIL-101(Cr)composite was characterized by XRD,FTIR,BET,SEM,XPS and ICP methods.Results indicated that the BMImPW@MIL-101(Cr)composites with PW^(3−) loading of 23.1–50.7 wt%were obtained,demonstrating that the“bottle around ship”method is beneficial to make full use of nanocages of MIL-101(Cr)to obtain expected high loading of active PW^(3−) .The BMImPW@MIL-101(Cr)exhibits excellent reusability with no evidence of leaching of active PW^(3−) and BMIm^(+),and well-preserved structure after successive cycles of regeneration and reuse.The significantly improved stability of BMImPW@MIL-101(Cr)as compared to HPW@MIL-101(Cr)is possibly because the leaching of the active PW^(3−) −sites can be greatly suppressed by forming large size of BMImPW owing to introduction of BMIm^(+)cation.The BMImPW@MIL-101(Cr)exhibited excellent catalytic activity for solvent free oxidative desulfurization of refractory sulfides.The enhanced oxidative desulfurization activity as compared to HPW@MIL-101(Cr)can be explained by the intimate contact of sulfides with active PW^(3−) sites owing the strong attraction of BMIm^(+)cation with the sulfides.
基金Project supported bythe National Nature Science Foundation of China (20276015)
文摘Y-Modified USY was prepared by ion exchange of USY slurry with 0.01 mol·L-1 Y(NO3)3. Phosphotungstic acid (HPW) catalyst supported on USY and Y-USY was prepared by an impregnation method. The materials were characterized by NH3-TPD, XRD, and N2 adsorption. The activity for the removal of thiophene was examined in a three-necked flask. The sulfur content of model compound was tested on WK-2D microcoulometric detector. The effect of yttrium and HPW content, reaction temperature and catalysts, activation temperature on the activity of catalysts were investigated. It was shown that the oxidation activity of thiophene decreased with the increase of Y content except for the catalyst of Y 5%. HPW content had limit influence on activity of catalysts. The optimal reaction temperature and activation temperature were 40 and 320 ℃, respectively.
文摘In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.
基金Supported by the National Natural Science Foundation of China(Grant No.21766039)the Natural Science Foundation of Shaanxi Province(Grant No.14JS111)+1 种基金the Major Project of Yan'an Science and Technology Bureau(Grant No.2016CGZH-10)the Project of Yan'an University(YDT2017-2)
文摘By combining the photochemical reaction and liquid–liquid extraction(PODS), we studied desulfurization of model fuel and FCC gasoline. The effects of air flow, illumination time, extractants, volume ratios of extractant/fuel, and catalyst amounts on the desulfurization process of PODS were analyzed in detail. Under the conditions with the air as oxidant(150 ml·min^(-1)), the mixture of DMF–water as extractant(the volume ratio of extractant/oil of 0.5) and photo-irradiation time of 2 h, the sulfur removal rate reached only 42.63% and 39.54% for the model and FCC gasoline, respectively. Under the same conditions, the sulfur removal rate increased significantly up to79% for gasoline in the presence of Cu_2O catalyst(2 g·L^(-1)). The results suggest that the PODS combined with a Cu_2O catalyst seems to be a promising alternative for sulfur removal of gasoline.
文摘The plasma oxidation desulfurization of thiophene in the liquid phase was studied. Under optimum conditions, the degree of desulfurization and selectivity of the solid sulfide formation can be achieved up to 79% and 47% respectively.
基金The project was supported by National Natural Science Foundation of China
文摘A few factors affecting plasma oxidation desulfurization of ethyl- thioether were investigated.Under the typical conditions,the conversion and degree of desulfurization of ethyl-thioether can be achieved up to 88% and 79% respectively.
基金The project was supported by National Natural Science Foundation of China.
文摘A few factors affecting plasma oxidation desulfurization of isobutyl mercaptan were investigated. Under the reasonable condition, the conversion and degree of desulfurization of isobutyl mercaptan can be achieved up to over 95% and 94% respectively.
基金Razi University Research Council for support of this work
文摘12-Tungstophosphoric acid(PW) supported on KSF montmorillonite, PW/KSF, was used as catalyst for deep oxidative desulfurization(ODS) of mixed thiophenic compounds in model oil and crude oil under mild conditions using hydrogen peroxide(H2O2) as an oxidizing agent. A one-factor-at-a-time method was applied for optimizing the parameters such as temperature, reaction time, amount of catalyst, type of extractant and oxidant-tosulfur compounds(S-compounds) molar ratio. The corresponding products can be easily removed from the model oil by using ethanol as the best extractant. The results showed high catalytic activity of PW/KSF in the oxidative removal of dibenzothiophene(DBT) and mixed thiophenic model oil under atmospheric pressure at 75 ℃ in a biphasic system. To investigate the oxidation and adsorption effects of crude oil composition on ODS, the effects of cyclohexene, 1,7-octadiene and o-xylene with different concentrations were studied.
基金supported by the National Nature Science Foundation of China(NSFC grant No.21303088)the Natural Science Foundation of Tianjin(14JCYBJC20000)the MOE Innovation Team(IRT13022 and IRT13R30)of China
文摘A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo(VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxidative desulfurization(ODS) process. The effect of hydrothermal temperature and crystallization temperature on ODS activity was investigated. The ODS activity of supported MoO2 catalysts with various MoO2 contents were also investigated. The mechanism for formation of MoO2 involving oxalic acid was proposed.
基金financially supported by the National Natural Science Foundation of China (Nos. 21506080 and 21766007)Natural Science Foundation of Jiangsu Province (No. BK20150485)+1 种基金Advanced Talents of Jiangsu University (No. 15JDG053)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Deep eutectic solvents(DESs) are a new class of green solvents analogous to ionic liquids due to their biodegradable capacity and low cost. However, the direct extractive desulfurization of diesel oil by DESs cannot meet the government’s standard. In this work, amphiphilic polyoxometalates were synthesized and characterized by FT-IR and mass spectrometry.The oxidative desulfurization results showed that benzothiophene(BT) could be completely removed by employing a [(CH)P(CH)]PMoO, DES(ChCl/2 Ac) and HOsystem. It was also found that the organic cation of catalysts played a positive role in oxidative desulfurization. The reaction conditions, such as reaction temperature and time, the amount of catalyst and DES and HO/S(O/S) molar ratio, were optimized. Different sulfides were tested to determine the desulfurization selectivity of the optimal reaction system, and it was found that 97.2% of dibenzothiophene(DBT) could be removed followed by 80.7% of 4-MDBT and 76.0% of 4,6-DMDBT. After reaction, the IR spectra showed that the catalyst [(CH)P(CH)]PMoOwas stable during the reaction process and the oxidative product was dibenzothiophene sulfone(DBTO). Furthermore, the catalyst can be regenerated and recycled for four runs with little loss of activity.
基金Supported by the National Nature Science Foundation of China(No.21476177)
文摘A serial of ordered meso-macroporous phosphotungstic acid(HPW) supported on SiO2 nanocomposites were successfully prepared by a homogeneous precipitation method, using monodispersed polystyrene(PS) microspheres and cationic surfactant as structure directing agent. These nanocomposites were used as catalysts for oxidative desulfurization(ODS) of model fuel. The materials were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), N2 adsorption-desorption isothrem, X-ray diffraction(XRD), and Fourier transform infrared spectra(FTIR). The characterization results suggested that the as-prepared material possessed ordered meso-macroporous architectures with Keggin type phosphotungstic acid dispersed homogeneously in SiO2 matrix. Under the selected reaction conditions, dibenzothiophene(DBT) in model fuel can be removed within 2 h at room temperature(30 ℃). In addition, only 1.2% of efficiency lose than the fresh catalyst even after 5 cycles.
基金Funded by the National Natural Science Foundation of China(21106008)the PetroChina Innovation Foundation(2013D-5006-0405)the Natural Science Foundation of Hubei Province(2011CDB007)
文摘A series of mesoporous phosphotungstic acid/alumina composites (HPW/Al_2O_3) with various HPW contents were synthesized by evaporation-induced self-assembly method. These composites were characterized by nitrogen adsorption-desorption, TEM, FTIR, and UV-vis, and were tested as catalysts in oxidation desulfurization of model fuel composed of dibenzothiophene (DBT) and hydrocarbon, using H202 as the oxidant. These composites exhibited high activity in catalytic oxidation of DBT in model fuel and good reusing ability. The best performance was achieved by using the mesoporous HPW/Al_2O_3 with 15wt% HPW content, which resulted in a DBT conversion of 98% after 2 h reaction at 343 K, and it did not show significant activity degradation after 3 recycles. Characterization results showed that the mesoporous structure of alumina and the Keggin structure of HPW were preserved in the formed composite. These results suggested that HPW/ Al_2O_3 could be a promising catalyst in oxidative desulfurization process.
基金the financial support of the Natural Science Foundation of China (Project No. 21003069)the Liaoning Province Doctoral Fund (Project No.201501105)
文摘The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scanning electron microscopy(SEM), infrared spectrometry(IR) and the Brunner-Emmet-Teller(BET) techniques. The WO_3/C composite, in comparison with the WO_3 and C_3N_4, features smaller particle size, bigger surface area and higher desulphurization performance. The influence of the reaction temperature, the catalyst dosage, the reaction time, the oxidant dosage, the sulfide type and the extractant dose on desulfurization reaction was studied. The results showed that the WO_3/C composite revealed a higher desulfurization activity than the WO_3. The desulfurization rate could reach up to 95.8% under optimal conditions covering a catalyst dosage of 0.02 g, a H_2O_2 amount of 0.2 mL, a 1-ethyl-3-methylimidazolium ethyl sulfate(EMIES) amount of 1.0 mL, a reaction temperature of 70 ℃ and a reaction time of 180 min. After five recycles, the desulfurization activity of catalyst did not significantly decline.
文摘In this work,in order to obtain deep clean gas oil,a novel organic–inorganic hybrid(n-C4H9)4N)7H5Si2W18Cd4O68@β-cyclodextrin(abbreviated as TBA-Si WCd@β-CD)composite was synthesized by supporting quaternary ammonium salt of sandwich-type polysilicotungstate onβ-cyclodextrin(TBA-SiWCd@β-CD)as an efficient catalyst for oxidative desulfurization(ODS)of gas oil.The successful composition of the materials explained by the formation of host–guest inclusion complex,which confirmed through FTIR,UV–vis,XRD,SEM,and EDX characterization analyses.Experimental results revealed that the levels of sulfur content and mercaptan compounds of gas oil lowered with 97%removal efficiency.Compared with the ODS treatment of gas oil,the TBA-Si WCd@β-CD composite showed an outstanding catalytic performance for the oxidation of dibenzothiophene(DBT)in the prepared model fuel.The main factors that influence the desulfurization efficiency and the kinetic study of the ODS process were investigated.The prepared heterogeneous catalyst was found to give remarkable reusability for five runs without a discernible decrease in its activity.This study suggested the potential application of the TBA-Si WCd@β-CD catalyst for removal of hazardous sulfur compounds from gas oil fuel.
基金financially supported by the National Nature Science Foundation of China (Nos. 21776116, 21576122, 21722604)Postdoctoral Foundation of China (No. 2017M621646)+1 种基金Postdoctoral Foundation of Jiangsu Province (No. 2018K083C)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman,UV–Vis, wide-angle XRD and N2adsorption–desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions.The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone.