Abstract The study on the catalysis of ionic liquids for alkylation of benzene with 1-octadecene to synthesize LAB （linear alkylbenzenes） was performed. The results showed that the most important factor that governe...Abstract The study on the catalysis of ionic liquids for alkylation of benzene with 1-octadecene to synthesize LAB （linear alkylbenzenes） was performed. The results showed that the most important factor that governed the conversion of olefin and selectivity of LAB was reaction temperature. Moreover, the effects of different ionic liquids and molar ratio of benzene to 1-octadecene on the conversion and selectivity were obviously in different degrees. The reaction temperature, molar ratio of benzene to 1-octadecene and the amount of catalyst were lower, compared with the traditional reaction technologies. The experimental results demonstrated that the ionic liquid had higher activity at 30℃, with over 98% selectivity of monoalkylbenzene and 100% conversion of the olefin at the molar ratio 0.08 of FeCl3 in ionic liquid to 1-octadecene and 10 for benzene to 1-octadecene.展开更多
Up to now the mechanism of Priedel-Crafts reactions catalyzed by ionic liquidhave not been fully understood, while carbocation mechanism was assumed. It was found that thesource of H^+ and the route of reaction initia...Up to now the mechanism of Priedel-Crafts reactions catalyzed by ionic liquidhave not been fully understood, while carbocation mechanism was assumed. It was found that thesource of H^+ and the route of reaction initiated the alkylation of benzene with ethylene catalyzedby [bmim]Cl/FeCl_3 ionic liquid. The fact that dewatered ionic liquids have catalytic activity forthe alkylation of benzene with ethylene suggests that there exists a new catalytic route. Thedistinctly Bronsted acid properties of 2-H in [bmim]Cl were found through FT-IR and HNMR analysis of[bmim]Cl after titration with water free KOH in alcohol solution. In addition, the chemical shiftsof proton on the [bmim]Cl ring, especially 2-H, are sensitive to the change of FeCl_3 content andshifted downfield when FeCl_3 was added into [bmim]Cl to form ionic liquid. Thus 2-H was easy to bedisengaged from imidazolium ring with formation of H^+ to initiate the reaction. Theisotope-substituted method was employed to prove this mechanism, through the GC-MS analysis ofalkylation products of deuterated benzene with ethylene. The route of alkylation catalyzed by FeCl_3ionic liquid was found to follow the carbocation mechanism, the resource of H^+ was presented andproved using HNMR analysis of ionic liquid to inspect the intensity change of 2-H. It was found thatthe intensity of 2-H reduced 23% after reaction showing that the H^+ arising from alkylationreaction was supplied by 2-H on the imidazole ring.展开更多
Fourier transform infrared spectroscopy(FTIR) and constant heating rate experiments were performed to study the low temperature oxidation of coal treated by an ionic liquid,1-allyl-3-methylimidazolium chloride.The ine...Fourier transform infrared spectroscopy(FTIR) and constant heating rate experiments were performed to study the low temperature oxidation of coal treated by an ionic liquid,1-allyl-3-methylimidazolium chloride.The inerting effect of the ionic liquid toward the low temperature oxidation process is discussed.The results show that:(1) The hydroxyl content associated with hydrogen bonds,the aliphatic methyl content,the methylene group content,and the ether oxygen bond content are reduced in the treated coal.At the same time the content of aromatic C@C bonds is constant but these chemical bonds weaken and some substituted aromatic hydrocarbon content increases while other types decrease.This demonstrates that(AMIm)Cl dissolves and destroys the coal surface microstructure;(2) The oxygen consumption of the treated coal is less than what is seen in raw coal.The CO,CO 2,C 2 H 4,and C 2 H 6 content from the treated coal is reduced compared to the untreated coal;(3) The apparent activation energy for the oxidizing reaction is different in the treated and raw coals.Micro-structural changes and macroscopic gas production allow us to conclude that(AMIm)Cl can effectively inhibit low temperature oxidation of coal.展开更多
bmim]Cl/FeCl3 ionic liquids (where bmim = 1-butyl-3-methylimidazolium) were characterized by XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), Raman and NMR (nuclear magnetic r...bmim]Cl/FeCl3 ionic liquids (where bmim = 1-butyl-3-methylimidazolium) were characterized by XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), Raman and NMR (nuclear magnetic resonance) spectra. The results show that Fe2Cl7 and FeCl4 ions are the principal anions in acidic ionic liquids, - - whose concentrations change with the content of FeCl3 and an equilibrium exists between them. An isosbestic point existing in FT-IR spectra indicates that an interaction involving at least two species occurs and their concentrations vary with acidity. Chemical shifts of the hydrogen located in the cations of ionic liquids are sensitive to the composition of ionic liquids. The change in chemical shifts may be explained in terms of anion-cation interactions. The chemical shifts of 2-H are affected by metal halides, which shift downfield and the 2-H is more deshielded with the increase in metal halides.展开更多
Photocatalytic oxidative desulfurization of gasoline in [BMIm]Cu2Cl3 ionic liquid was studied. A 500-W high-pressure mercury lamp was used as the light source for irradiation, nano-TiO2 was used as the photocatalyst a...Photocatalytic oxidative desulfurization of gasoline in [BMIm]Cu2Cl3 ionic liquid was studied. A 500-W high-pressure mercury lamp was used as the light source for irradiation, nano-TiO2 was used as the photocatalyst and air was introduced by a gas pump to supply O2 as the oxidant. Influence of the ratio of V（ionic liquid） to V（oil） and the TiO2 addition on the desulfurization rate of gasoline was investigated. An oxidative kinetics equation was founded. The results showed that the [BMIm]CUECl3 ionic liquid was an effective extractant for the desulfurization of gasoline. The appropriate TiO2 addition was 0.05 g in 50 mL of reaction mixture. The yield of desulfurized gasoline could reach 98.2% after being subjected to reaction for 2 h under the conditions of adopting a ratio of V（ionic liquid）： V（oil）=1：4, an air flow of 100 mL/min and a TiO2 addition dosage of 0.05 g. The kinetics reaction for photo-oxidation of gasoline was a first-order reaction with an apparent rate constant of 1.9664 h^-1 and a half-time of 0.3525 h.展开更多
Two novel ionic liquids,[Bzmim]Cl and[Bzmim][AuCl_(4)],were successfully synthesized and characterized by ^(1)H NMR spectroscopy,single crystal structure analysis and quantum mechanical calculations.Meanwhile,multiple...Two novel ionic liquids,[Bzmim]Cl and[Bzmim][AuCl_(4)],were successfully synthesized and characterized by ^(1)H NMR spectroscopy,single crystal structure analysis and quantum mechanical calculations.Meanwhile,multiple supramolecular interactions of[Bzmim][AuCl_(4)](hydrogen bonds,Cl…π,Au…π interactions and π-π stacking)were found between the N-methylimidazolium cation and AuCl_(4)^(-).Interestingly,the interactions made it easy for[Bzmim][AuCl_(4)]to form a 3D supramolecular structure.Thus,a series of N-methylimidazolium-based poly(ionic liquids)were synthesized to recover Au(Ⅲ)in aqueous solution.They show high adsorption capacity and excellent selectivity for tetrachloroaurate anions which can be used as solid phase extraction agents over a wide temperature range.Notably,the acid thiourea can desorb Au(Ⅲ)from polymeric ionic liquids(PILs),thus they also exhibit excellent recyclability.Among them,PS-b-PVBnMeImCl-5.9 has the highest efficiency for Au(Ⅲ)recovery after five adsorption-desorption cycles.Compared with the Raman spectroscopy results of gold-containing PS-b-PVBnMeImCl-5.9,1H NMR of[Bzmim][AuCl4]revealed that the Au(Ⅲ)recovery mechanism by polymeric ionic liquids was due to a combination of electrostatic interactions and multiple weak intermolecular interactions.展开更多
基金Supported by the National Natural Science Foundation of China （No.20276038） and Beijing Natural Science Foundation （No.2052010）.
文摘Abstract The study on the catalysis of ionic liquids for alkylation of benzene with 1-octadecene to synthesize LAB （linear alkylbenzenes） was performed. The results showed that the most important factor that governed the conversion of olefin and selectivity of LAB was reaction temperature. Moreover, the effects of different ionic liquids and molar ratio of benzene to 1-octadecene on the conversion and selectivity were obviously in different degrees. The reaction temperature, molar ratio of benzene to 1-octadecene and the amount of catalyst were lower, compared with the traditional reaction technologies. The experimental results demonstrated that the ionic liquid had higher activity at 30℃, with over 98% selectivity of monoalkylbenzene and 100% conversion of the olefin at the molar ratio 0.08 of FeCl3 in ionic liquid to 1-octadecene and 10 for benzene to 1-octadecene.
文摘Up to now the mechanism of Priedel-Crafts reactions catalyzed by ionic liquidhave not been fully understood, while carbocation mechanism was assumed. It was found that thesource of H^+ and the route of reaction initiated the alkylation of benzene with ethylene catalyzedby [bmim]Cl/FeCl_3 ionic liquid. The fact that dewatered ionic liquids have catalytic activity forthe alkylation of benzene with ethylene suggests that there exists a new catalytic route. Thedistinctly Bronsted acid properties of 2-H in [bmim]Cl were found through FT-IR and HNMR analysis of[bmim]Cl after titration with water free KOH in alcohol solution. In addition, the chemical shiftsof proton on the [bmim]Cl ring, especially 2-H, are sensitive to the change of FeCl_3 content andshifted downfield when FeCl_3 was added into [bmim]Cl to form ionic liquid. Thus 2-H was easy to bedisengaged from imidazolium ring with formation of H^+ to initiate the reaction. Theisotope-substituted method was employed to prove this mechanism, through the GC-MS analysis ofalkylation products of deuterated benzene with ethylene. The route of alkylation catalyzed by FeCl_3ionic liquid was found to follow the carbocation mechanism, the resource of H^+ was presented andproved using HNMR analysis of ionic liquid to inspect the intensity change of 2-H. It was found thatthe intensity of 2-H reduced 23% after reaction showing that the H^+ arising from alkylationreaction was supplied by 2-H on the imidazole ring.
基金support from the National Natural Science Foundation of China (No.51074159)The Graduate Scientific Research Innovation Programme of Jiangsu Province Ordinary University (No. CXZZ12_0957)
文摘Fourier transform infrared spectroscopy(FTIR) and constant heating rate experiments were performed to study the low temperature oxidation of coal treated by an ionic liquid,1-allyl-3-methylimidazolium chloride.The inerting effect of the ionic liquid toward the low temperature oxidation process is discussed.The results show that:(1) The hydroxyl content associated with hydrogen bonds,the aliphatic methyl content,the methylene group content,and the ether oxygen bond content are reduced in the treated coal.At the same time the content of aromatic C@C bonds is constant but these chemical bonds weaken and some substituted aromatic hydrocarbon content increases while other types decrease.This demonstrates that(AMIm)Cl dissolves and destroys the coal surface microstructure;(2) The oxygen consumption of the treated coal is less than what is seen in raw coal.The CO,CO 2,C 2 H 4,and C 2 H 6 content from the treated coal is reduced compared to the untreated coal;(3) The apparent activation energy for the oxidizing reaction is different in the treated and raw coals.Micro-structural changes and macroscopic gas production allow us to conclude that(AMIm)Cl can effectively inhibit low temperature oxidation of coal.
文摘bmim]Cl/FeCl3 ionic liquids (where bmim = 1-butyl-3-methylimidazolium) were characterized by XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), Raman and NMR (nuclear magnetic resonance) spectra. The results show that Fe2Cl7 and FeCl4 ions are the principal anions in acidic ionic liquids, - - whose concentrations change with the content of FeCl3 and an equilibrium exists between them. An isosbestic point existing in FT-IR spectra indicates that an interaction involving at least two species occurs and their concentrations vary with acidity. Chemical shifts of the hydrogen located in the cations of ionic liquids are sensitive to the composition of ionic liquids. The change in chemical shifts may be explained in terms of anion-cation interactions. The chemical shifts of 2-H are affected by metal halides, which shift downfield and the 2-H is more deshielded with the increase in metal halides.
基金the Research Foundation of Hebei Province Education Department(2007440)
文摘Photocatalytic oxidative desulfurization of gasoline in [BMIm]Cu2Cl3 ionic liquid was studied. A 500-W high-pressure mercury lamp was used as the light source for irradiation, nano-TiO2 was used as the photocatalyst and air was introduced by a gas pump to supply O2 as the oxidant. Influence of the ratio of V（ionic liquid） to V（oil） and the TiO2 addition on the desulfurization rate of gasoline was investigated. An oxidative kinetics equation was founded. The results showed that the [BMIm]CUECl3 ionic liquid was an effective extractant for the desulfurization of gasoline. The appropriate TiO2 addition was 0.05 g in 50 mL of reaction mixture. The yield of desulfurized gasoline could reach 98.2% after being subjected to reaction for 2 h under the conditions of adopting a ratio of V（ionic liquid）： V（oil）=1：4, an air flow of 100 mL/min and a TiO2 addition dosage of 0.05 g. The kinetics reaction for photo-oxidation of gasoline was a first-order reaction with an apparent rate constant of 1.9664 h^-1 and a half-time of 0.3525 h.
基金supported by the National Natural Science Foundation of China(Grant 51474118).
文摘Two novel ionic liquids,[Bzmim]Cl and[Bzmim][AuCl_(4)],were successfully synthesized and characterized by ^(1)H NMR spectroscopy,single crystal structure analysis and quantum mechanical calculations.Meanwhile,multiple supramolecular interactions of[Bzmim][AuCl_(4)](hydrogen bonds,Cl…π,Au…π interactions and π-π stacking)were found between the N-methylimidazolium cation and AuCl_(4)^(-).Interestingly,the interactions made it easy for[Bzmim][AuCl_(4)]to form a 3D supramolecular structure.Thus,a series of N-methylimidazolium-based poly(ionic liquids)were synthesized to recover Au(Ⅲ)in aqueous solution.They show high adsorption capacity and excellent selectivity for tetrachloroaurate anions which can be used as solid phase extraction agents over a wide temperature range.Notably,the acid thiourea can desorb Au(Ⅲ)from polymeric ionic liquids(PILs),thus they also exhibit excellent recyclability.Among them,PS-b-PVBnMeImCl-5.9 has the highest efficiency for Au(Ⅲ)recovery after five adsorption-desorption cycles.Compared with the Raman spectroscopy results of gold-containing PS-b-PVBnMeImCl-5.9,1H NMR of[Bzmim][AuCl4]revealed that the Au(Ⅲ)recovery mechanism by polymeric ionic liquids was due to a combination of electrostatic interactions and multiple weak intermolecular interactions.
