The hydroformylation of 1-hexene catalyzed by rhodium-TPPTS complexes in the ionic liquid [bmim]BF 4 was studied. The activity and selectivity of the rhodium-TPPTS complexes in [bmim]BF 4 were much higher than those r...The hydroformylation of 1-hexene catalyzed by rhodium-TPPTS complexes in the ionic liquid [bmim]BF 4 was studied. The activity and selectivity of the rhodium-TPPTS complexes in [bmim]BF 4 were much higher than those reported in other ionic liquids. The TOF of 1-hexene and selectivity for aldehyde were 1508 h -1 and 92%, respectively, under the optimum conditions. The high activity of the catalyst is ascribed to the absence of halide ions as well as the much higher solubility of hydrogen and rhodium-TPPTS complexes in [bmim]BF 4 than in [bmim]PF 6.展开更多
Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at diffe...Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at different temperatures were measured by using a modified boiling point method in various concentrations of （16.66%, 33.7%）, （17.4%, 33.9%） and （16.5%, 32%） mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation （AAD） was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.展开更多
Adsorption properties of an adsorbent or a catalyst towards adsorbates are crucial in the process of adsorption separation or catalytic reaction. Surface morphology and structure of adsorbents have a significant impac...Adsorption properties of an adsorbent or a catalyst towards adsorbates are crucial in the process of adsorption separation or catalytic reaction. Surface morphology and structure of adsorbents have a significant impact on the adsorption properties. In this study, a novel acidic ionic liquid, 1-butyl-3-(triethoxysilylpropyl)imidazolium hydrogen sulfate(i.e., [BTPIm][HSO_4]), was synthesized and subsequently grafted onto the MCM-36 zeolite for the regulation of its adsorption properties towards isobutane and 1-butene. The resultant [BTPIm][HSO_4]-immobilized MCM-36(i.e., MCM-36-IL) was characterized by FT-IR, XPS, XRD, SEM, TG/DTG and N_2 adsorption–desorption measurement. It was found that the specific surface area, micropore volume and mesopore volume of the MCM-36 support underwent a reduction upon the immobilization of ionic liquid,while the surface density of acid increased from 0.0014 to 0.0035 mmol·m^(-2). The adsorption capacity of isobutane and 1-butene on the MCM-36-IL was determined by a static volumetric method. Results demonstrated that the interaction between isobutane and MCM-36-IL was enhanced and the interaction between 1-butene and MCM-36-IL was reduced. As a result, a tunable adsorption ratio of isobutane/1-butene on MCM-36 was achieved.With the increase in surface density of acid and the tunable adsorption ratio of isobutane and 1-butene on the functionalized MCM-36, the acidic ionic liquid-immobilized zeolites are beneficial to obtain an improved reaction yield and a prolonged catalyst life in the reactions catalyzed by solid acid.展开更多
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
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
文摘The hydroformylation of 1-hexene catalyzed by rhodium-TPPTS complexes in the ionic liquid [bmim]BF 4 was studied. The activity and selectivity of the rhodium-TPPTS complexes in [bmim]BF 4 were much higher than those reported in other ionic liquids. The TOF of 1-hexene and selectivity for aldehyde were 1508 h -1 and 92%, respectively, under the optimum conditions. The high activity of the catalyst is ascribed to the absence of halide ions as well as the much higher solubility of hydrogen and rhodium-TPPTS complexes in [bmim]BF 4 than in [bmim]PF 6.
基金Supported by the National Natural Science Foundation of China(No. 20376004).
文摘Vapor pressure values of binary systems water ＋ ethanol, water ＋ ionic liquid 1-propyl-3- methylimidazolium bromide （[PMIM] [Br]）, ethanol ＋ [PMIM] [Br] and ternary system water ＋ ethanol ＋ [PMIM] [Br] at different temperatures were measured by using a modified boiling point method in various concentrations of （16.66%, 33.7%）, （17.4%, 33.9%） and （16.5%, 32%） mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation （AAD） was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.
基金Supported by the National Natural Science Foundation of China(No.21276163,and No.21576168)
文摘Adsorption properties of an adsorbent or a catalyst towards adsorbates are crucial in the process of adsorption separation or catalytic reaction. Surface morphology and structure of adsorbents have a significant impact on the adsorption properties. In this study, a novel acidic ionic liquid, 1-butyl-3-(triethoxysilylpropyl)imidazolium hydrogen sulfate(i.e., [BTPIm][HSO_4]), was synthesized and subsequently grafted onto the MCM-36 zeolite for the regulation of its adsorption properties towards isobutane and 1-butene. The resultant [BTPIm][HSO_4]-immobilized MCM-36(i.e., MCM-36-IL) was characterized by FT-IR, XPS, XRD, SEM, TG/DTG and N_2 adsorption–desorption measurement. It was found that the specific surface area, micropore volume and mesopore volume of the MCM-36 support underwent a reduction upon the immobilization of ionic liquid,while the surface density of acid increased from 0.0014 to 0.0035 mmol·m^(-2). The adsorption capacity of isobutane and 1-butene on the MCM-36-IL was determined by a static volumetric method. Results demonstrated that the interaction between isobutane and MCM-36-IL was enhanced and the interaction between 1-butene and MCM-36-IL was reduced. As a result, a tunable adsorption ratio of isobutane/1-butene on MCM-36 was achieved.With the increase in surface density of acid and the tunable adsorption ratio of isobutane and 1-butene on the functionalized MCM-36, the acidic ionic liquid-immobilized zeolites are beneficial to obtain an improved reaction yield and a prolonged catalyst life in the reactions catalyzed by solid acid.
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.
