[bmin]Cl/[FeCl3]离子液体催化的苯与1-十八烯烷基化反应

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.     

New Alkylation Route of Benzene with Ethylene Catalyzed by [bmim]Cl/FeCl_3 Ionic Liquid

Up to now the mechanism of Friedel-Crafts reactions catalyzed by ionic liquid have not been fully understood, while carbocation mechanism was assumed. It was found that the source of H and the route of reaction initiated the alkylation of benzene with ethylene catalyzed by [bmim]Cl/FeCl3 ionic liquid. The fact that dewatered ionic liquids have catalytic activity for the alkylation of benzene with ethylene suggests that there exists a new catalytic route. The distinctly Bronsted acid properties of 2-H in [bmim]Cl were found through FT-IR and HNMR     

Isobaric vapor–liquid equilibrium for binary system of aniline+methyl-N-phenyl carbamate

In this study,the quasi-static ebulliometric method was used to measure both of the vapor pressures of methyl N-phenyl carbamate(MPC),and the isobaric vapor–liquid equilibrium(VLE) data of the aniline and MPC binary system.The measured vapor pressure data of MPC,at different temperature ranging from 369.60 to 389.54 K,fitted well with the Antoine equation.The VLE data for the aniline and MPC system at(2.00,4.00,6.00,7.00 and 8.00) k Pa were correlated by both of nonrandom two-liquid(NRTL) and Wilson models.The parameters of the two models were obtained by regressing the experimental data,with the absolute temperature deviations of 0.54 K and 0.53 K,respectively.The relative volatility of the binary system calculated was all far more than 1,which gives the conclusion that the high purity MPC can be separated from aniline and MPC binary system by rectification or distillation technology.     

Ionic liquid catalyzed solvent-free synthesis of chalcone and its derivatives under mild conditions

An ionic liquid(IL) catalyzed solvent-free process was developed for the direct synthesis of chalcone and its derivatives by using substituted acetophenones and benzaldehydes via aldol reaction under mild conditions. A series of acidic and basic ILs were selected and screened. The influences of cations and reaction conditions on product yield and selectivity were systematically investigated. The [Bmim]OH was identified as the optimal IL, with the highest yield and selectivity reaching up to 96.7% and 100%, respectively. A reaction mechanism-based kinetic model was established and regressed with experimental data, revealing the b-Hydroxylketone dehydrolysis with activation barrier of 37.8 k J·mol~(-1) was observed as the ratecontrolling step.     

离子液体催化的芳烃氯甲基化反应

Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance of different ionic liquid catalysts for toluene chloromethylation was also studied. The reaction was found to proceed under mild conditions with excellent conversion （up to 90%） in the absence of Lewis acids. The ionic liquids could be recycled and reused without loss of their catalytic activities.     

苯胺在超临界水中氧化反应路径

An aqueous solution of aniline was oxidized in supercritical water with a flow reactor under the conditions of 25 MPa, 300％ excess oxygen, 2.351×10-4 mol*L-1 aniline .GC-MS analysis of the oxidation products extracted from the aqueous reactor effluent permitted identification of compounds such as azobenzene, phenazine and acetic acid. The products could be classified as dimers,single-ring or ring-opening produces,carboxylic acids and ultimate products.The contents of dimers (such as azobenzene and phenazine) were greater than other products.A reaction network consistent with the experimental observations was developed. The study revealed that aniline might be oxidized to ultimate products through two parallel pathways. The formation of dimers such as azobenzene, phenazine and the further oxidation of these dimers were the main pathways. It was indicated experimentally that the rate controlling step of aniline oxidation was the further oxidation of azobenzene and phenazine, but not the further oxidation of organic acid such as acetic acid, formic acid and so on.     

Highly selective synthesis for 4,4′-bisphenol F from phenol and formaldehyde catalyzed with [C_4mim][HSO_4] ionic liquid

The effects of N-methylimidazole cation [Cnmim] with different alkyl chain lengths, the types of cations and anions of ionic liquids and the reaction parameters on the catalytic activity and the selectivity for 4,4′-bisphenol F were investigated. The hydrogen bonding between the hydroxyl of phenol and the C2-position hydrogen of imidazole moiety in hydrophilic imidazole-based ionic liquid has important influence on the selectivity for 4,4′-bisphenol F, and under the conditions of the molar ratio of phenol/[C4mim][HSO4] 1:1, reaction temperature65 °C and the theoretical molar ratio of phenol/formaldehyde 2:1, the selectivity for 4,4′-bisphenol F reached69.1%. Compared with the high phenol/formaldehyde ratio reported in literatures, the low molar ratio of phenol/formaldehyde and the low reaction temperature can greatly reduce energy consumption, and has important significance for industrial application.     

[bmim]Cl／FeCl3离子液体催化苯与乙烯烷基化反应的新型机理

Up to now the mechanism of Friedel-Crafts reactions catalyzed by ionic liquid have not been fully understood, while carbocation mechanism was assumed. It was found that the source of H and the route of reaction initiated the alkylation of benzene with ethylene catalyzed by [bmim]Cl/FeCl3 ionic liquid. The fact that dewatered ionic liquids have catalytic activity for the alkylation of benzene with ethylene suggests that there exists a new catalytic route. The distinctly 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 shifts of proton on the [bmim]Cl ring, especially 2-H, are sensitive to the change of FeCl3 content and shifted downfield when FeCl3 was added into [bmim]Cl to form ionic liquid. Thus 2-H was easy to be disengaged from imidazolium ring with formation of H^ to initiate the reaction. The isotope-substituted method was employed to prove this mechanism, through the GC-MS analysis of alkylation products of deuterated benzene with ethylene. The route of alkylation catalyzed by FeC13 ionic liquid was found to follow the carbocation mechanism, the resource of H was presented and proved using HNMR analysis of ionic liquid to inspect the intensity change of 2-H. It was found that the intensity of 2-H reduced 23% after reaction showing that the H arising from alkylation reaction was supplied by 2-H on the imidazole ring.     

新型多磺酸基离子液体催化对甲酚与叔丁醇的烷基化反应

The alkylation of p-cresol with tert-butanol(TBA)to 2-tert-butyl-p-cresol(TBC)catalyzed by a novel multiple-SO3H functioned ionic liquid(IL1)was investigated.Meanwhile,the catalytic activity of this novel ionic liquid was compared with other four traditional ionic liquids.The results showed that IL1 has superior catalytic activity to other four traditional ionic liquids with the conversion of 85.3%and selectivity of 95.2%.Also,the reaction conditions were investigated to obtain the optimum conditions.Operational simplicity,small amount of usage,high activity,reusability and selectivity are the key features of this methodology.     

Kinetics of water-isocyanate reaction in N,N-dimethylformamide

The uncatalyzed reaction of p-tolyl isocyanate (p-TI) with water in N,N-dimethylformamide (DMF) was investigated by high performance liquid chromatography (HPLC).The reactions were carried out at different temperatures from 293 K to 323 K,using various molar ratios of water to p-TI.DMF,as a special amide,was proved to be an efficient catalyst for water-isocyanate reaction.Under the reaction conditions in this study,substituted urea was the only final product observed.An appreciable amount of intermediate p-toluidine was detected.Concentrations of the isocyanate group as well as the amine and urea were determined as a function of time.New kinetic equations were deduced for each of the substance on the basis of a multistep mechanism,instead of a simple second order reaction as usual.Kinetic constants were calculated using the software MATLAB.Furthermore,the effects of temperature and concentrations of reactants on the reaction rate and amine content were discussed.The activation energy of each step was also determined.     

Recycling and Activity Recovery of Chloroaluminate Ionic Liquid as Catalyst for Alkylation of Benzene with 1-Dodecene

Performances of 1-butyl-3-methylimidazolium aluminium chloride ([BMIM]Cl-AlCl3) ionic liquid as catalyst for the alkylation of benzene with long chain olefins were investigated in a continuous operation mode. A small pilot plant with continuous mixing-reacting-separating-recycling functions, equipped with a static mixer reactor, a tube packed with metal Al thread and a combined liquid-liquid settling phase separator, was introduced as an alternative. The results showed that the continuous fast mixing and separation of ionic liquid catalyst from reactant mixture could be synchronously accomplished within a wider flow rate ratio range of the recycling reaction mixture to the ionic liquid catalyst. The recycling of chloroaluminate ionic liquid was realized. ICP-AES detection results of Al content in the reactants proves that in-situ Al compensation to the reaction system may be an important choice to prolong the stable running time of moisture-sensitive ionic liquid [BMIM]Cl-AlCl3 when feedstock inevitably contains trace water. It suggests that the activity of chloroaluminate ionic liquid is recovered under the in-situ Al compensation operation.     

氯化胆碱·xZnCl_2离子液体在生物柴油制备中的应用(英文)

The inexpensive and moisture-stable Lewis-acidic ionic liquids were prepared and applied for transesterification of soybean oil to biodiesel.The influences of molar ratio of methanol to soybean oil,reaction temperature and amount of ionic liquids were investigated.The transesterification of soybean oil to biodiesel catalyzed by choline chloride·xZnCl2 ionic liquids showed many advantages such as mild conditions and lower cost.On the other hand,the non-ideal yield and complicated separation between biodiesel and soybean oil were also investigated and analyzed.The improvement on the systems of choline chloride·xZnCl2 was proposed for further investigation.     

SO_3H-功能化离子液体催化4,4'-MDC合成反应

The synthesis of methylene diphenyl dimethylcarbamate (4,4′-MDC) from methyl N-phenyl carbonate (MPC) and formaldehyde (HCHO) was conducted in the presence of sulfonic acid-functionalized ionic liquids (ILs) as dual solvent-catalyst. The influences of the kind of anion in the ionic liquids, reaction conditions and the recycle of the ionic liquid on 4,4′-MDC synthesis reaction were investigated. In addition, the acid strength of ILs was determined by the Hammett method with UV-visible spectroscopy, and the acid strength-catalytic activity relationship was correlated. The activity estimation results showed that [HSO3-bmim]CF3SO3 was the optimal dual solvent-catalyst. Under the suitable reaction conditions of 70°C, 40 min, molar ratio of nMPC/nHCHO 10/1 and mass ratio of WILs/WMPC 4.5/1, the yield of 4,4′-MDC based on HCHO was 89.9 % and the selectivity of 4,4′-MDC with respect to MPC was 74.9%. Besides, [HSO3-bmim]CF3SO3 was reused four times after being purified and no significant loss in the catalytic activity was observed.     

Studies on Macro-kinetics of Gas Phase Polymerization of Butadiene with Rare-earth Catalyst

The study of the kinetics of gas phase polymerization of butadiene with heterogeneous catalyst based on neodymium (Nd) was carried out. The effects of reaction temperature, reaction pressure, dispersing medium, and types of catalyst on kinetics of polymerization were investigated. A kinetic model with two kinds of active sites was proposed. The results show that the effects of the reaction temperature and the types of dispersing medium and catalyst on the kinetic performance of polymerization are significant, and that the combined model of first and second order decay of active site of catalyst can be used to describe the phenomena.     

Lipase-catalyzed Synthesis of Caffeic Acid Phenethyl Ester in Ionic Liquids： Effect of Specific Ions and Reaction Parameters

Caffeic acid phenethyl ester（CAPE） is a rare, naturally occurring phenolic food additive. This work systematically reported fundamental data on conversion of caffeic acid（CA）, yield of CAPE, and reactive selectivity during the lipase-catalyzed esterification process of CA and phenylethanol（PE） in ionic liquids（ILs）. Sixteen ILs were selected as the reaction media, and the relative lipase-catalyzed synthesis properties of CAPE were measured in an effort to enhance the yield of CAPE with high selectivity. The results indicated that ILs containing weakly coordinating anions and cations with adequate alkyl chain length improved the synthesis of CAPE. [Emim][Tf2 N] was selected as the optimal reaction media. The optimal parameters were as follows by response surface methodology（RSM）： reaction temperature, 84.0 °C; mass ratio of Novozym 435 to CA, 14︰1; and molar ratio of PE to CA, 16 ︰ 1. The highest reactive selectivity of CAPE catalyzed by Novozym 435 in [Emim][Tf2 N] reached 64.55%（CA conversion 98.76% and CAPE yield 63.75%, respectively）. Thus, lipase-catalyzed esterification in ILs is a promising method suitable for CAPE production.     

Application of the shrinking core model to the kinetics of zinc oxide desulfurization

The kinetics of H_2S removal by zinc oxide desulfurizer was studied through thermogravimetricanalysis.The experimental results show that desulfurization rate was controlled,at high temperatureand low conversion,by the chemical reaction rate,and at low temperature and high conversion by thegrain diffusion rate.The reaction is first order with respect to H_2S concentration in the differentcontrolled stages.The kinetic behavior can be modeled through the employment of the shrinking coremodel.The values of the model parameters were determined.The variation tendencies with temperatureand concentration of H_2S at the controlled stages were discussed.     

复合离子液体催化碳酸乙烯酯水解制备乙二醇(英文)

An ionic liquid system of [Bmim]X/[Bmim]OH (X Cl, BF4, and PF6,) was developed for the hydrolysis of ethylene carbonate to ethylene glycol. The important parameters, such as the variety of ionic liquids, molar ratio of [Bmim]X to [Bmim]OH, amount of ionic liquid, molar ratio of water to ethylene carbonate, reaction temperature, pressure and reaction time, were investigated systematically. Excellent yield (>93%) and high selectivity (99.5%) of ethylene glycol were achieved. Under the optimum reaction conditions, the ionic liquid system could be reused at least five times and the selectivity of ethylene glycol remained higher than 99.5%.     

A solvent-free,selective liquid phase hydrogenation of nitroarenes to aniline in slurry bubble mode on porous NiMo bimetallic catalyst

Ni Mo bimetallic catalysts were prepared by a solid reaction method. On the Ni Mo catalyst, the selective liquid phase hydrogenation of nitrobenzene to aniline was achieved in slurry bubble mode. And the high yields(98.9%) were obtained under the conditions of 80 °C, solvent-free and atmospheric pressure. The effect of Mo on the catalytic behavior of Ni based catalyst was investigated. The characterization displayed that the inclusion of Mo could improve the specific surface area and pore volume, and the solid reaction method made metal Mo enrichment on the surface of catalyst. These two aspects should be responsible for excellent catalytic performance of Ni Mo catalyst. In sum, we described a simple and efficient Ni Mo catalyst and provided a facile and green procedure for liquid phase hydrogenation of nitrobenzene to aniline.     

[bupy]BF4-AlCl3离子液体上甲苯和间戊二烯的烷基化反应

The alkylation of toluene with 1,3-pentadiene to produce pentyltoluene was carded out to obtain 2,6-dimethylnaphalene, which is an important intermediate during the production of 2,6-naphthalene dicarboxylic acid. Based on our previous work using anhydrous AlCl3 as catalyst, [bupy]BF4-AlCl3 ionic liquids were employed to catalyze the reaction of 1,3-pentadiene with toluene. The experimental results show that [bupy]BF4-AlCl3 ionic liquids are suitable for the reaction especially when the molar ratio of AlCl3 to [bupy]BF4 is 1.75 ： 1, and the reaction could proceed at the temperature as low as 0℃. It could be as active as pure AlCl3, but much more environmentally friendly.     

Measurement of thermal conductivity,viscosity and density of ionic liquid [EMIM][DEP]-based nanofluids☆

This article studied experimentally the effect of multi-wall carbon nanotubes(MWCNTs)on the thermo physical properties of ionic liquid-based nanofluids.The nanofluids were composed of ionic liquid,1-ethyl-3-methylimidazolium diethylphosphate [EMIM][DEP],or its aqueous solution[EMIM][DEP](1)+ H_2O(2)and MWCNTs without any surfactants.The thermal conductivity,viscosity and density of the nanofluids were measured experimentally.The effects of the mass fraction of MWCNTs,temperature and the mole fraction of water on the thermo physical properties of nanofluids were studied.Results show that the thermal conductivity of nanofluids increases within the range of 1.3%–9.7% compared to their base liquids,and have a well linear dependence on temperature.The viscosity and density of the nanofluids exhibit a remarkable increase compared with those of the base liquids.Finally,the correlation of the effective thermal conductivity and viscosity of the nanofluids was made using the models in the literatures.