非均相羰基氧化一步合成碳酸二苯酯的研究(Ⅴ)筛选催化剂及优化合成条件

Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity. The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main phase was Lao.szPbo.asMnOa and the average diameter could be about 25.4nm. The optimuna conditions for synthesis of DPC with Pd/LasPbyMnOz were determined by orthogonal experiments and the experimental results showed that reaction temperature was the first factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas phase also had significant effect on selectivity of DPC. The optimum reaction conditions were catalyst/phenol mass ratio l to 50, pressure 4.5MPa, volume concentration of O2 25%, reaction temperature 60℃ and reaction time 4 h. The maximum yield and average selectivity could reach 13% and 97% respectively in the     

Non-phosgene synthesis of hexamethylene-1,6-diisocyanate from thermal decomposition of hexamethylene-1,6-dicarbamate over Zn–Co bimetallic supported ZSM-5 catalyst

A non-phosgene route for the synthesis of hexamethylene-1,6-diisocyanate(HDI) was developed via catalytic decomposition of hexamethylene-1,6-dicarbamate(HDC) over Zn–Co bi-metallic supported ZSM-5 catalyst.The catalyst was characterized by FTIR and XRD analyses. Three solvents dioctyl sebacate(DOS), dibutyl sebacate(DBS) and 1-butyl-3-methylimidazolium tetrafluoroborate(BMIMBF_4) were investigated and compared; DOS gave better performance. The catalytic performances for thermal decomposition of HDC to HDI using DOS as solvent were then investigated, and the results showed that, under the optimized reaction conditions, i.e.,10 wt%concentration of HDC in DOS, 250 °C temperature, 60 min reaction time, 83.8% yield of HDI had been achieved over Zn–Co/ZSM-5. Decomposition of the intermediate hexamethylene-1-carbamate-6-isocyanate(HMI) over Zn–Co/ZSM-5 in DOS solvent was further studied and the results indicated that yield of HDI from HMI reached to 69.6%(98.6% HDI selectively) at 270 °C, which further increased the yield of the total HDI(HDI_(tol)) to as high as 95.0%. Recycling of catalyst showed that HDI and HMI yield slightly decreased, and by-product yield increased after the catalyst was reused for 4 times. At last possible reaction mechanism was proposed.     

含磺酰氯基吡唑啉酮类偶氮化合物的合成

Chlorosulfonyl-containing pyrazolone azo compounds (2a, 2b) have been prepared by reaction of the corresponding sodium sulfonate (la, lb) with thionyl chloride in the presence of a catalytic quantity of N,Ndimethylformamide in dry benzene. The effects of reaction temperature, time, catalyst and solvent amount on the yield of 2a and 2b were investigated. The results show that chlorination of 1a and 1b under optimal conditions gives 2a and 2b in 95.5% and 99.2% yield respectively. The given method is facile and suitable for large-scale synthesis.     

Synthesis of Chlorosulfonyl-containing Pyrazolone Azo Compounds with Thionyl Chloride-DMF System

Chlorosulfonyl-containing pyrazolone azo compounds (2a, 2b) have been prepared by reaction of the corresponding sodium sulfonate (la, 1b) with thionyl chloride in the presence of a catalytic quantity of N,N-dimethylformamide in dry benzene. The effects of reaction temperature, time, catalyst and solvent amount on the yield of 2a and 2b were investigated. The results show that chlorination of 1a and 1b under optical conditions gives 2a and 2b in 95.5% and 99.2% yield respectively. The given method is facile and suitable for large-scale synthesis.     

The biomimetic catalytic synthesis of acetal compounds using β-cyclodextrin as catalyst

Based on the principle of biomimetic catalysis, β-cyclodextrin was applied to the acetalation reaction as a facile and efficient catalyst, and the synthesis was environmentally friendly with atomic economy. The influencing factors of the acetalation reaction e.g. the reaction time, the volume of water-carrying agent,the molar ratio of catalyst to benzaldehyde and the molar ratio of glycol to benzaldehyde had been studied.The yield of benzaldehyde glycol acetal would reach a maximum of 81.3% under the conditions approached.Six of other acetals were also synthesized. Moreover, a plausible reaction mechanism for the formation of acetal had been proposed.     

双组分Cu催化硅和氯甲烷直接合成甲基氯硅烷简

A bi-component catalyst comprising CuC1 and metallic copper was used in the direct synthesis of me- thylchlorosilane to study the catalytic synergy between the different copper sources. The catalyst exhibited high ac- tivity and high selectivity of dimethyldichlorosilane （M2） in the stirred bed reactor. The effect of the proportion of CuC1 used was studied and 10%-30% CuC1 gave the best yield of M2. The use of CuC1 decreased the induction pe- riod of reaction, improved the selectivity in the induction stage, and gave a longer stable stage. These results sug- gest that bi-comoonent catalyst has advantazes in the direct synthesis reaction.     

The effect of operating conditions on acylation of 2-methylnaphthalene in a microchannel reactor

Acylation of 2-methylnaphthalene(2-MN) is a very important reaction in organic synthesis,and the effiency of the continuous reactor is more than one of the batch reactor.Considering that the Friedel–Crafts acylation is a rapid exothermic reaction,in this study,we perform the acylation of 2-MN in a stainless steel microchannel flow reactor,which is characterized by high mass and heat transfer rates.The effect of reactant ratio,mixing temperature,reaction temperature,and reaction time on product yield and selectivity were investigated.Under the optimal conditions,2-methyl-6-propionylnaphthalene(2,6-MPN) was obtained in 85.8% yield with 87.5% selectivity.Compared with the conventional batch system,the continuous flow microchannel reactor provides a more efficient method for the synthesis of 2,6-MPN.     

Production of biodiesel from palm fatty acid distillate using sulfonated-glucose solid acid catalyst:Characterization and optimization

A palm fatty acid distillate (PFAD) has been used for biodiesel production. An efficient sulfonated-glucose acid catalyst (SGAC) was prepared by sulfonation to catalyze the esterification reaction. The effect of three variables i.e. methanol-to-PFAD molar ratio, catalyst amount and reaction time, on the yield of PFAD esters was studied by the response surface methodology (RSM). The optimum reaction conditions were:12.2:1 methanol-to-PFAD molar ratio, 2.9%catalyst concentration and 134 min of time as predicted by the RSM. The reaction under the optimum conditions resulted in 94.5%of the free fatty acid (FFA) conversion with 92.4%of the FAME yield. The properties of the PFAD esters were determined according to biodiesel standards.     

Selective oxidation of cyclopentene with H_2O_2 by using H_3PW_(12)O_(40) and TBAB as a phase transfer catalyst

The selective oxidation of cyclopentene by aqueous H_2O_2 using H_3PW_(12)O_(40) and tetrabutyl ammonium bromide(TBAB) as a phase transfer catalyst has been investigated. The results show that the presence of TBAB significantly improved the oxidation selectivity of cyclopentene. The effects of the reaction conditions on the conversion of cyclopentene were investigated in detail. The optimal reaction conditions are as follows: the H_3PW_(12)O_(40) to TBAB molar ratio, 1:1–1:3; H_3PW_(12)O_(40) to cyclopentene molar ratio,0.54:100–0.64:100; and molar ratio of H_2O_2 to cyclopentene, 1.6:1. The conversion reached to 59.8% in 4h at 35.0 °C, while the selectivity of glutaraldehyde was 38.0% and the selectivity of 1,2-cyclopentanediol was 55.6%. In addition, a route for oxidation of cyclopentene by aqueous H_2O_2 using a heteropoly acid and quaternary ammonium salt as a phase transfer catalyst was proposed.     

Performance characteristics of fluidized bed syngas methanation over Ni-Mg/Al2O3 catalyst

The performance characteristics of isothermal fluidized bed syngas methanation for substitute natural gas are investigated over a self-made Ni–Mg/Al2O3 catalyst. Via atmospheric methanation in a laboratory fluidized bed reactor it was clarified that the CO conversion varied in 5% when changing the space velocity in 40–120 L·g?1·h?1 but the conversion increased obviously by raising the superficial gas velocity from 4 to 12.4 cm·s?1. The temperature at 823 K is suitable for syngas methanation while obvious deposition of uneasy-oxidizing Cγoccurs on the catalyst at temperatures around 873 K. From a kinetic aspect, the lowest reaction temperature is suggested to be 750 K when the space velocity is 60 L·g?1·h?1. Raising the H2/CO ratio of the syngas increased proportionally the CO conversion and CH4 selectivity, showing that at enough high H2/CO ratios the active sites on the catalyst are sufficient for CO adsorption and in turn the reaction with H2 for forming CH4. Introducing CO2 into the syngas feed suppresses the water gas shift and Boudouard reactions and thus increased H2 consumption. The ratio of CO2/CO in syngas should be better below 0.52 because varying the ratio from 0.52 to 0.92 resulted in negligible increases in the H2 conversion and CH4 selectivity but decreased the CH4 yield. Introducing steam into the feed gas affected little the CO conversion but decreased the selectivity to CH4. The tested Ni–Mg/Al2O3 catalyst manifested good stability in structure and activity even in syngas containing water vapor.     

Functionalized metal–organic frameworks with strong acidity and hydrophobicity as an efficient catalyst for the production of 5-hydroxymethylfurfural

In the dehydration of fructose to 5-hydroxymethyl furfural(HMF), in situ produced water weakens the acid strength of the catalyst and causes the rehydration of HMF, causing unsatisfactory catalytic activity and selectivity. In this work, a class of benzenesulfonic acid-grafted metal–organic frameworks with strong acidity and hydrophobicity is obtained by the direct sulfonation method using 4-chlorobenzenesulfonic acid as sulfonating agent. The resultant MOFs have a specific surface area of greater than 250 m~2·g~(-1), acid density above 1.0 mmol·g~(-1), and water contact angle up to 129°. The hydrophobic MOF-Ph SO_3 H exhibits both higher catalytic activity and selectivity than MOF-SO_3 H in the HMF synthesis due to its better hydrophobicity and olephilicity. Moreover, the catalyst has a high recycled stability. At last, fructose is completely converted, and 98.0% yield of HMF is obtained under 120 °C in a DMSO solvent system. The successful preparation of the hydrophobic acidic MOF provides a novel hydrophobic catalyst for the synthesis of HMF.     

Desulfurization of liquid hydrocarbon fuels via Cu_2O catalyzed photooxidation coupled with liquid–liquid extraction

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.     

Evaluation of an improved epichlorohydrin synthesis from dichloropropanol using a microchemical system

Synthesizing epichlorohydrin (ECH) from dichloropropanol (DCP) is a complicated reaction due to the partial decomposition of ECH under harsh conditions. A microchemical system can provide a feasible platform for improving this process by conducting a separation once full conversion has been achieved. In this work, referring to a common DCP feed used in industry, the reaction performance of mixed DCP isomers with NaOH in the microchemical system on various time scales was investigated. The operating window for achieving high conver-sion and selectivity was on a time scale of seconds, while the side reactions normal y occurred on a time scale of minutes. Plenty of Cl?ions together with a high temperature were proved to be critical factors for ECH hydrolysis. A kinetic study of alkaline mediated ECH hydrolysis was performed and the requirements for an improved ECH synthesis were proposed by combining quantitative analysis using a simplified reaction model with experimen-tal results on the time scale of minutes. Compared with the conventional distillation process, this new strategy for ECH synthesis exploited microchemical system and decoupled the reaction and separation with potentials of higher productivity and better reliability in scaling up.     

Optimal reaction conditions for pyridine synthesis in riser reactor

Pyridine has been generally synthesized by aldehydes and ammonia in a turbulent fluidized-bed reactor. In this paper, a novel riser reactor was proposed for pyridine synthesis. Experiment result showed that the yield of pyridine and 3-picoline decreased, but the selectivity of pyridine over 3-picoline increased compared to turbulent fluidized-bed reactor. Based on experimental data, a modified kinetic model was used for the determination of optimal operating condition for riser reactor. The optimal operating condition of riser reactor given by this modified model was as follows: The reaction temperature of 755 K, catalyst to feedstock ratio(CTFR) of 87, residence time of 3.8 s and initial acetaldehydes concentration of 0.0029 mol·L~(-1)(acetaldehydes to formaldehydes ratio by mole(ATFR) of 0.65 and ammonia to aldehydes ratio by mole(ATAR) of 0.9, water contention of 63 wt%(formaldehyde solution)).     

固体超强酸催化剂SO2-4/TiO2-MoO3的制备及其催化合成缩醛（酮）

SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The optimum conditions were also found, that is, the mass ratio of MoO3 used in the compound is 25%, the calcination temperature 450℃, and the soaked consistency of H2SO4 is 0.5mol.L^-1. Then it was applied in the catalytic synthesis of six similar important ketals and acetals as catalyst and revealed high catalytic activity. Under the condition that the molar ratio of aldehyde/ketone to glycol was 1:1.5, the mass ratio of the catalyst to the reactants was 0.5% and the reaction time 1.0 h, the yield of ketals and acetals reached up to 63.2%. The catalyst can be easily recovered and reused.     

Synthesis and characterization of poppy seed oil methyl esters

Response surface methodology(RSM) was used to determine the optimum conditions of the methanolysis of crude poppy seed oil using Na OCH3 as catalyst. The experiments were run according to five levels, four variable central composite rotatable design(CCRD) using RSM. The reaction variables, i.e., molar ratio of methanol/oil(3:1–9:1), catalyst concentration(0.5 wt%–1.25 wt% Na OCH3), reaction temperature(25–65 °C), and reaction time(20–90 min) were studied. We demonstrated that the molar ratio of methanol/oil, catalyst concentration,and reaction temperature were the significant parameters affecting the yield of poppy seed oil methyl esters(PSOMEs). The optimum transesterification reaction conditions, established using the RSM, which offered a89.35% PSOME yield, were found to be 7.5:1 molar ratio of methanol/oil, 0.75% catalyst concentration, 45 °C reaction temperature, and 90 min reaction time. The proposed process provided an average biodiesel yield of more than 85%. A linear correlation was constructed between the observed and predicted values of the yield.The gas chromatography(GC) analyses have shown that PSOMEs contain linoleic-, oleic-, palmitic-, and stearic-acids as main fatty acids. The FTIR spectrum of the PSOMEs was also analyzed to confirm the completion of the transesterification reaction. The fuel properties of the PSOMEs were discussed in light of biodiesel standards(ASTM D 6751 and EN 14214).     

单过氧丁二酸氧化环己酮合成ε-己内酯(英文)

In the absence of catalyst, 70% hydrogen peroxide was used to oxidize succinic anhydride to solid monoperoxysuccinic acid（PSA）. Then PSA was applied to synthesis of ε-caprolactone（ε-CL） by oxidation of cyclohexanone in the heterogeneous system. In order to achieve material recycle, solid precipitated in the process of synthesizing ε-CL was dehydrated via reactive distillation followed by recrystallization to prepare succinic anhydride, which was characterized by IR（infrared spectra） and1HNMR（1H nuclear magnetic resonance）. Effects of molar ratio of PSA to cyclohexanone, acetic acid dosage, reaction temperature, reaction time on conversion of cyclohexanone, yield and selectivity of ε-CL were investigated respectively. The results indicated that conversion of cyclohexanone, yield and selectivity of ε-CL were upto 98.1%, 97.5% and 99.4% respectively under the optimal conditions. In addition, in the process of synthesizing succinic anhydride, the optimal yield of succinic anhydride reached 67.4%.     

低温水相一步合成钛酸钡:热力学模型化及实验合成研究

A thermodynamic model has been developed to determine the reaction conditions favoring low temperature direct synthesis of barium titanate (BaTiO3). The method utilizes standard-state thermodynamic data for solid and aqueous species and a Debye-Hǔckel coefficients model to represent solution nonideality. The method has been used to generate phase stability diagrams that indicate the ranges of pH and reagent concentrations, for which various species predominate in the system at a given temperature. Also, yield diagrams have been constructed that indicate the concentration, pH and temperature conditions for which different yields of crystalline BaTiO3 can be obtained. The stability and yield diagrams have been used to predict the optimum synthesis conditions (e.g.,reagent concentrations, pH and temperature). Subsequently, these predictions have been experimentally verified.As a result, phase-pure perovskite BaTiO3 has been obtained at temperature ranging from 55 to 85℃ using BaCl2,TiCl4 as a source for Ba and Ti. and NaOH as a orecioitator.     

金属卟啉催化的甲苯氧化及工艺优化

Catalytic activities of a series of metalloporphyrin complexes in selective aerobic oxidation of toluene were investigated.The effects of different central metal ions in metalloporphyrins[T（p-Cl）PPMCl（M=Fe,Co,Mn,Cu）] on the reaction course had been examined and it was found that T（p-Cl）PPCu presented the highest catalytic activity in the reaction.The reaction conditions of toluene oxidation were optimized by using orthogonal experiment design.Five relevant factors were investigated：temperature,air pressure,catalyst loading,air flow rate and reaction time.The effects of the five factors on both toluene conversion and total yield of benzaldehyde and benzyl alcohol were discussed.The research results showed that the reaction temperature was the most significant factor influencing toluene oxidation.On the basis of the margin analysis,the optimum conditions for the toluene conversion and the total yield of benzaldehyde and benzyl alcohol respectively were achieved,under which the toluene conversion was up to 14.67%and the total yield of benzaldehyde and benzyl alcohol reached 5.89%.     

1,6-己二胺与氨基甲酸甲酯非均相CeO2催化合成1,6-己二氨基甲酸甲酯（英文）

The efficient synthesis of dimethylhexane-1,6-dicarbamate (HDC) from 1,6-hexanediamine (HDA) and methyl carbonate over a series of heterogeneous catalysts (e.g., MgO, Fe2O3, Mo2O3, and CeO2) was investigated. The reaction pathway was confirmed as an alcoholysis reaction through a series of designed experiments. Under optimized conditions, 100%HDA conversion with 83.1%HDCtotal and 16.9%polyurea was obtained using a one-step with high temperature procedure with CeO2 as the catalyst. A new two-step with variable temperature technol-ogy was developed based on the reaction pathway to reduce the polyurea yield. Using the proposed method, the HDCtotal yield reached 95.2%, whereas the polyurea yield decreased to 4.8%. The CeO2 catalyst showed high stability and did not exhibit any observable decrease in the HDC yield or any structural changes after four recycling periods. ? 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.