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
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
The Hartree-Fock method has been employed to investigate the electronic structures of EMIM＋（1- ethyl-3-methylimidazolium＋）, AlCl4^-, and EMIM＋-AlCl4^-. Full optimization and frequency analyses of EMIM＋, AlCl4^-,...The Hartree-Fock method has been employed to investigate the electronic structures of EMIM＋（1- ethyl-3-methylimidazolium＋）, AlCl4^-, and EMIM＋-AlCl4^-. Full optimization and frequency analyses of EMIM＋, AlCl4^-, ten initial EMIM＋-AlCl4^- geometries have been carried out using the Gaussian-94 soft-package at 6- 31＋G（d,p） basis set level for hydrogen, carbon, nitrogen, chlorine, and aluminum atoms. The electronic structures of the lowest energy of EMIM＋-AlCl4^-pairs, single EMIM^＋, and AlCl4^- have been comparatively studied. The calculated results showed that the optimized EMIM^＋-AlCl4^-pair conformer of lowest energy was AlCl4^-outside the five-ring plane between methyl group and ethyl group with a H6--C122 distance of 2.7 A. The frequency analyses suggested that all stationary points were minimum points because of no imaginary frequency appearing, and the assigned frequencies were in agreement with experimental report. The interaction energy between EMIM^＋ and AlCl4^-was 776.2 kJ/mol.展开更多
FeCl3-based ionic liquid [Bmim]Br/FeCl3 with lower viscosity was synthesized and its structure was character-ized with FT-IR spectroscopy. The denitrogenation performance of the ionic liquid was investigated using the...FeCl3-based ionic liquid [Bmim]Br/FeCl3 with lower viscosity was synthesized and its structure was character-ized with FT-IR spectroscopy. The denitrogenation performance of the ionic liquid was investigated using the Fushun shale diesel fraction with high nitrogen content. Experimental results showed that the ionic liquid presented good denitrogenation performance and the basic N and total N removal efficiency can reach 95.29% and 89.77% under conditions covering a tem-perature of 30 ℃, an IL/oil mass ratio of 1:1, an extraction time of 30 min, and a settling time of 2 h. Correspondingly, the basic N and total N contents in shale diesel fraction dropped from the original 5454 μg/g and 9832 μg/g to 257 μg/g and 1006 μg/g, respectively. In addition, the basic-N removal efficiency can still reach 60% at an IL/oil mass ratio of 1:7 during four recycles of the ionic liquid.展开更多
Reaction of alkanones with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the corresponding ct-bromoalkanones with excellent yields.
The anodic behavior of neodymium in acidic AlCl3-1-ethyl-3-methyl-imidazolium chloride （AIC13-EMIC） ionic liquid was investigated by conducting linear sweep voltammeter and chonopotentiometry. The viscosity of Nd di...The anodic behavior of neodymium in acidic AlCl3-1-ethyl-3-methyl-imidazolium chloride （AIC13-EMIC） ionic liquid was investigated by conducting linear sweep voltammeter and chonopotentiometry. The viscosity of Nd dissolved ionic liquid and the surface morphologies of Nd were characterized using an Ostwald viscometer and a scanning electron microscope, respectively. The chemical composition of Nd surface was indentified by Raman spectra. The results showed that dissolution of Nd under anodic polarization occurred after the breakdown of oxide films. A viscous layer formed at the interface of Nd/ionic liquid during the galvanostatic process of 5 and 20 mA/cm^2. The formation of viscous layer was attributed to the accumulation of Nd dissolved AlCl3-EMIC ionic liquid, which had high viscosity. The oxide films could be removed thoroughly and the surface of Nd was homogeneous without etching pits, when viscous layer formed in the anodic process. Otherwise, the surface showed a pitting morphology.展开更多
Poly[ 2, 2-（m.phenylene） -5, 5-bibenzimidazole] （mPBI） were synthesized by mixing 3, 3＇, 4, 4＇-tetraaminobiphenyl and isophthallc acid in 1 -butyl-3 -methyUmidazolinm chloride （ E BMIM] CI）. Intrinsic viscosit...Poly[ 2, 2-（m.phenylene） -5, 5-bibenzimidazole] （mPBI） were synthesized by mixing 3, 3＇, 4, 4＇-tetraaminobiphenyl and isophthallc acid in 1 -butyl-3 -methyUmidazolinm chloride （ E BMIM] CI）. Intrinsic viscosity of mPBI polymers was 0.67 dL/g which was measured in 96% sulfuric acid. The polymer was characterized by Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （ 1H-NMR ）, and thermogravimetric analysis （TGA）. The effects of polymerization conditions on the intrinsic viscosity of mPBI were investigated. It showed that the molecular weight of polymer mainly depended on pre-reaction time and reaction temperature. Comparison of structure and properties of mPBI synthesized in ionic liquids（ILs） and polyphosphoric acid was also reported. It indicates that the ionic liquids are a kind of good solvents in synthesis process of m_PBI and ionic liquids mainly affect molecular weight of mPBL展开更多
A new cellulose solvent ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was used to treat wheat straw and steam-exploded wheat straw (SEWS) in order to improve the enzymatic hy- drolysis rates, while the ...A new cellulose solvent ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was used to treat wheat straw and steam-exploded wheat straw (SEWS) in order to improve the enzymatic hy- drolysis rates, while the water was used as the con- trol. The enzymatic hydrolysis results showed that the hydrolysis rates of materials treated with [BMIM]Cl were improved. The hydrolysis rate of treated wheat straw could reach 70.37% and the SEWS could be completely hydrolyzed, while hydrolysis rates of the wheat straw and SEWS treated with water were 42.78% and 68.78% under the same conditions, re- spectively. The FTIR analysis and polymerization degree measurement indicated that the hydrolysis rates improvement was attributed to the decrease of the polymerization degrees of cellulose and hemi- cellulose, the absolute crystallinity degree of cellu- lose and the increase of its reaction accessibility.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.
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.
文摘The Hartree-Fock method has been employed to investigate the electronic structures of EMIM＋（1- ethyl-3-methylimidazolium＋）, AlCl4^-, and EMIM＋-AlCl4^-. Full optimization and frequency analyses of EMIM＋, AlCl4^-, ten initial EMIM＋-AlCl4^- geometries have been carried out using the Gaussian-94 soft-package at 6- 31＋G（d,p） basis set level for hydrogen, carbon, nitrogen, chlorine, and aluminum atoms. The electronic structures of the lowest energy of EMIM＋-AlCl4^-pairs, single EMIM^＋, and AlCl4^- have been comparatively studied. The calculated results showed that the optimized EMIM^＋-AlCl4^-pair conformer of lowest energy was AlCl4^-outside the five-ring plane between methyl group and ethyl group with a H6--C122 distance of 2.7 A. The frequency analyses suggested that all stationary points were minimum points because of no imaginary frequency appearing, and the assigned frequencies were in agreement with experimental report. The interaction energy between EMIM^＋ and AlCl4^-was 776.2 kJ/mol.
基金financial support from the Doctoral Funds of Liaoning Provincial Natural Science Foundation (201601323)
文摘FeCl3-based ionic liquid [Bmim]Br/FeCl3 with lower viscosity was synthesized and its structure was character-ized with FT-IR spectroscopy. The denitrogenation performance of the ionic liquid was investigated using the Fushun shale diesel fraction with high nitrogen content. Experimental results showed that the ionic liquid presented good denitrogenation performance and the basic N and total N removal efficiency can reach 95.29% and 89.77% under conditions covering a tem-perature of 30 ℃, an IL/oil mass ratio of 1:1, an extraction time of 30 min, and a settling time of 2 h. Correspondingly, the basic N and total N contents in shale diesel fraction dropped from the original 5454 μg/g and 9832 μg/g to 257 μg/g and 1006 μg/g, respectively. In addition, the basic-N removal efficiency can still reach 60% at an IL/oil mass ratio of 1:7 during four recycles of the ionic liquid.
文摘Reaction of alkanones with 1-butyl-3-methylimidazolium tribromide （[Bmim]Br3） under solvent-free conditions, selectively gave the corresponding ct-bromoalkanones with excellent yields.
基金Project supported by the National Natural Science Foundation of China(51271166)
文摘The anodic behavior of neodymium in acidic AlCl3-1-ethyl-3-methyl-imidazolium chloride （AIC13-EMIC） ionic liquid was investigated by conducting linear sweep voltammeter and chonopotentiometry. The viscosity of Nd dissolved ionic liquid and the surface morphologies of Nd were characterized using an Ostwald viscometer and a scanning electron microscope, respectively. The chemical composition of Nd surface was indentified by Raman spectra. The results showed that dissolution of Nd under anodic polarization occurred after the breakdown of oxide films. A viscous layer formed at the interface of Nd/ionic liquid during the galvanostatic process of 5 and 20 mA/cm^2. The formation of viscous layer was attributed to the accumulation of Nd dissolved AlCl3-EMIC ionic liquid, which had high viscosity. The oxide films could be removed thoroughly and the surface of Nd was homogeneous without etching pits, when viscous layer formed in the anodic process. Otherwise, the surface showed a pitting morphology.
基金Natural Science Foundation of Shanghai,China(No.09ZR1401500)
文摘Poly[ 2, 2-（m.phenylene） -5, 5-bibenzimidazole] （mPBI） were synthesized by mixing 3, 3＇, 4, 4＇-tetraaminobiphenyl and isophthallc acid in 1 -butyl-3 -methyUmidazolinm chloride （ E BMIM] CI）. Intrinsic viscosity of mPBI polymers was 0.67 dL/g which was measured in 96% sulfuric acid. The polymer was characterized by Fourier transform infrared spectroscopy （FTIR）, nuclear magnetic resonance （ 1H-NMR ）, and thermogravimetric analysis （TGA）. The effects of polymerization conditions on the intrinsic viscosity of mPBI were investigated. It showed that the molecular weight of polymer mainly depended on pre-reaction time and reaction temperature. Comparison of structure and properties of mPBI synthesized in ionic liquids（ILs） and polyphosphoric acid was also reported. It indicates that the ionic liquids are a kind of good solvents in synthesis process of m_PBI and ionic liquids mainly affect molecular weight of mPBL
文摘A new cellulose solvent ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) was used to treat wheat straw and steam-exploded wheat straw (SEWS) in order to improve the enzymatic hy- drolysis rates, while the water was used as the con- trol. The enzymatic hydrolysis results showed that the hydrolysis rates of materials treated with [BMIM]Cl were improved. The hydrolysis rate of treated wheat straw could reach 70.37% and the SEWS could be completely hydrolyzed, while hydrolysis rates of the wheat straw and SEWS treated with water were 42.78% and 68.78% under the same conditions, re- spectively. The FTIR analysis and polymerization degree measurement indicated that the hydrolysis rates improvement was attributed to the decrease of the polymerization degrees of cellulose and hemi- cellulose, the absolute crystallinity degree of cellu- lose and the increase of its reaction accessibility.
