MoVPO型催化剂上氨氧化合成2-氰基吡嗪

The mechanism of 2-cyanopyrazine prepared from 2-methylpyrazine （2-MP） by catalytic ammoxidation has been explained by the theory of appropriate structure of group. A new catalyst of MoVPO was developed. The effects of catalyst promoter phosphorus and supports were investigated. The catalyst containing P, V and Mo in molar ratio of 1.4 ： 1 ： 0.02 and supported on activated alumina and prepared by impregnation method exhibits good activity and selectivity. Reaction factors such as reaction temperature, space velocity, feed composition and service life of catalyst were investigated. Optimum reaction conditions （the volume space velocity of 0.2h-1, the reaction temperature of 380 ~C and molar ratio of 1 ： 7.8 ： 8 ： 8 for 2-MP, water, oxygen and ammonia） were obtained. Selectivity of 93% and yield of 86% could be achieved under these conditions.     

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     

The Intermetallic Catalysts for Oxidative Esterification of Methacrolein to Methyl Methacrylate

A series of supported intermetallic Pb-Pb catalysts were prepared with the impregnation method by changing the support (silica, molecular sieve or g-alumina ) and the pore size. The chemical states of the two metals were characterized by XPS analysis, the process for producing methyl methacrylate based on the direct oxidative esterification of methacrolein with methanol in the presence of oxygen was performed in a slurry reactor with the above-mentioned catalysts. The influence of the calcination temperature and the kinds of support as well as the pore size on catalytic activity had been extensively investigated. Under the conditions of temperature at 80℃, catalyst 3.8% (w) and the reaction time 2 h, the conversion rate of methacrolein reached 85%, the selectivity and the yield of methyl methacrylate were 90% and 76.5%, respectively.     

Performance of Ni/Nano-ZrO2catalysts for CO preferential methanation简

Large surface areas nano-scale zirconia was prepared by the self-assembly route and was employed as support in nickel catalysts for the CO selective methanation. The effects of Ni loading and the catalyst calcination temperature on the performance of the catalyst for CO selective methanation reaction were investigated. The cata- lysts were characterized by Brunauer-Emmett-Teller （BET）, transmission electron microscope （TEM）, X-ray dif- fraction （XRD） and temperature-programmed reduction （TPR）. The results showed that the as-synthesized Ni/nano-ZrO2 catalysts presented high activity for CO methanation due to the interaction between Ni active particle and nano zir- conia support. The selectivity for the CO methanation influenced significantly by the particle size of the active Ni species. The exorbitant calcination resulted in the conglomeration of dispersive Ni particles and led to the decrease of CO methanation selectivity. Among the catalysts studied, the 7.5% （by mass） Ni/ZrO2 catalyst calcinated at 500℃ was the most effective for the CO selective methanation. It can preferentially catalyze the CO methanation with a higher 99% conversion in the CO/CO2 competitive methanation system over the temperature range of 260-280℃, while keeping the CO2 conversion relatively low.     

钙钛矿型混合导体透氧膜SrFe0.6Cu0.3Ti0.1O3－δ的制备与表征

Dense membrane with the composition of SrFe0.6Cu0.3Ti0.1O3-δ （SFCTO） was prepared by solid state reaction method. Oxygen permeation flux through this membrane was investigated at operating temperature ranging from 750℃ to 950℃ and different oxygen partial pressure. XRD measurements indicated that the compound was able to form single-phased perovskite structure in which part of Fe was replaced by Cu and Ti. The oxygen desorption and the reducibility of SFCTO powder were characterized by thermogravimetric analysis and temperature programmed reduction analysis, respectively. It was found that SFCTO had good structure stability under low oxygen pressure at high temperature. The addition of Ti increased the reduction temperature of Cu and Fe. Performance tests showed that the oxygen permeation flux through a 1.5 mm thick SFCTO membrane was 0.35-0.96 ml·min ^-1·cm^-2 under air/helium oxygen partial pressure gradient with activation energy of 53.2 kJ·mol^-1. The methane conversion of 85%, CO selectivity of 90% and comparatively higher oxygen permeation flux of 5 ml·min^-1·cm^- 2 were achieved at 850℃, when a SFCTO membrane reactor loaded with Ni-Ce/Al2O3 catalyst was applied for the partial oxidation of methane to syngas.     

[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.     

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%.     

REOx掺杂的ZrO2催化剂催化羟乙基吡咯烷酮脱水反应性能

Catalyst plays an important role in the dehydration of N-（hydroxylethyl）pyrrolidone （NHP） to prepare N-vinyl-pyrrolidone （NVP）. At present, NVP yield is only about 30% on commercial ZrO2 catalyst. A coupled precipitation and solid dispersion technique was designed to prepare the nano-ZrO2 catalyst, in which rare earth metal oxides （REOx） was used as electronic promoter. The results indicated that the catalyst doped REOx （S-1.0） exhibits the optimum performance of NHP dehydration at moderate conditions. NHP conversion and NVP selectivity are respectively 97.0%, 82.3%. Of special interest is that the indexes of the catalyst （S-1.0-1.0） are up to 98.4% and 89.2% respectively. Furthermore, this catalyst bears the good stability. It means that nano-ZrO2 doped REOx catalyst might be a potential commercial catalyst for the NHP dehydration.     

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 catalytic activity of SBA-15 supported catalysts for styrene oxidation

Cu(II) and Mn(II) metals embedded on mesoporous SBA-15 were synthesized by co-precipitation technique.The support and catalysts were characterized by SEM–EDX,TEM,BET,XRD and ICP-AES methods.The catalytic activity of these catalysts was evaluated for styrene oxidation at various reaction conditions such as styrene to TBHP mole ratio,temperature,catalyst amount by using TBHP as an oxidizing agent.Major reaction products were styrene oxide and benzaldehyde and highest styrene conversion(97.3%) was observed at styrene to TBHP mole ratio of 1:4,temperature at 80 °C and 20 mg of catalyst.Further,the recyclability of the catalysts was observed and found that they can be recycled three times without major loss in their activity and selectivity.     

合成甲基异丙基酮和二乙基酮的Na-Pd/ZrO2-MnOx-ZnO催化剂的制备与表征

考察了催化剂组成、还原温度和反应条件对Na Pd/ZrO2 MnOx ZnO催化剂性能的影响,并用BET、XRD和NH3 TPD、CO2 TPD等技术对催化剂进行了表征。研究表明,用此方法制备的ZrO2 无晶相衍射峰,是无定型的。当n(Zr)∶n(Mn)∶n(Zn) =2 0∶(0 2~0 5)∶1 0时,既无明显的ZnO晶相衍射峰,也无明显的MnOx晶相衍射峰,ZrO2、MnOx、ZnO生成固溶体,并引起平均孔径增大和比表面积减小。ZrO2、MnOx、ZnO生成固溶体的孔径较大的催化剂具有更高的活性。x(Pd) =0 25%、x(Na) =0 29%、n(Zr)∶n(Mn)∶n(Zn) =2 0∶(0 2~0 5)∶1 0的催化剂,在常压、温度643K、原料液相空速1 0h-1条件下,甲基乙基酮的转化率达39 6%,甲基异丙基酮和二乙基酮的选择性分别为45 5%、32 2%。     

液液相转移催化法合成过氧化甲乙酮

在相转移催化剂的作用下 ,2 -丁酮由 3 0 %的双氧水氧化制取过氧化甲乙酮。通过正交试验和考察原料配比、反应温度、相转移催化剂用量、反应时间对产品质量的影响 ,确定了最佳工艺条件为 n双氧水 ∶n丁酮 =1 .5∶ 1 ,相转移催化剂采用三乙基苄基氯化铵 ,用量占总质量的 0 .4% ,在氨基磺酸的催化下 ,反应温度 5℃左右 ,反应时间 3 0 min,稀释剂用邻苯二甲酸二丁酯 ,产品经测定 ,对不饱和聚酯的凝胶时间适宜并稳定 ,产品活性氧含量高。     

甲基异丙酮的合成技术及市场分析

介绍了甲基异丙酮的多种合成路线,主要有异丁醛-乙酸法、异丁酸-乙酸法、甲基乙基酮-甲醛法和异戊二烯法。概述了国内外甲基异丙酮的的开发和生产现状,并分析了国内市场现状,最后对我国甲基异丙酮今后的发展方向提出了几点建议。     

甲基异丙基酮的合成研究进展

归纳介绍了甲基异丙基酮的不同合成路线,根据起始原料不同分类,主要有异丁酸法、异丁醛法、异戊二烯法和甲乙酮法等。简要评价了各方法的工艺特点。     

仲丁醇脱氢催化剂性能

采用XRD、TPR、BET和N2O滴定法对仲丁醇脱氢催化剂YTDH-1G与对比剂A进行表征,并采用常压固定床反应器考察两种催化剂的仲丁醇脱氢活性和甲乙酮选择性。结果表明,催化剂中添加Zr O2后可以提高催化剂活性组分的分散度,改善催化剂的还原性能。催化剂YTDH-1G表明的Cu比表面积和分散度明显大于对比剂A。在考察的实验范围,催化剂YTDH-1G的催化活性和产物选择性优于对比剂A,对工艺条件的适应性较强,可在较宽的温度和空速范围使用,具有较好的工业应用前景。     

Microreactor technology for synthesis of ethyl methyl oxalate from diethyl oxalate with methanol and its kinectics

This study focused on the performances and kinetics of the transesterification reaction of diethyl oxalate with methanol to prepare ethyl methyl oxalate via microreactor technology. The conversion of 79.8% of diethyl oxalate (DEO) and the selectivity of 65.9% of ethyl methyl oxalate (EMO) was obtained under the following optimized conditions: the mole ratio of methanol to diethyl oxalate was 3.3:1, the temperature was 35°C, the K₂CO₃ catalyst concentration was 15 mg/mL, and the residence time was 2.30 minutes. In the temperature range of 25°C to 38°C, the simplified dynamic model was found to obtain the reaction order (α = 2.30), frequency factor (k₀ = 2.377 × 10⁵), and apparent activation energy (E = 31.86 kJ/mol). The macroscopic dynamic equation was derived from the experimental result of the transesterification reaction of two feedstocks, which can be obtained through a series of calculations.     

2,3-丁二醇液相脱水制备甲乙酮反应研究

研究了2,3-丁二醇液相脱水生成甲乙酮(MEK)的反应,对浓硫酸、对甲苯磺酸、ZSM-5分子筛以及自制固体酸的催化活性进行比较,发现对甲苯磺酸对2,3-丁二醇脱水制备甲乙酮的催化性能较好。以对甲苯磺酸做催化剂,优化实验装置,通过对实验结果进行分析得到最佳的反应条件为:采用反应精馏装置,催化剂用量为2,3-丁二醇质量的3%,塔顶温度控制在70～80℃,反应时间为5.5h,产品收率可达到78.9%。此外,还考察了脱水副反应生成的高沸点缩合物的水解反应,硫酸用量为缩合物质量的1%,反应时间为100min,MEK收率为93.3%。     

Pd-Pb/Al2O3催化剂上甲基丙烯醛氧化酯化合成甲基丙烯酸甲酯

引言 甲基丙烯酸甲酯(MMA)是生产有机玻璃(PMMA)的核心单体,目前主要采用丙酮氰醇法(ACH法)生产,此法工艺流程长、原子经济性低(约47%)、经济效益差、环境污染严重,因此,开发一条绿色高效的合成工艺路线意义重大.     

过氧化甲乙酮合成研究

论述了过氧化甲乙酮的合成方法，用阳离子交换树脂催化剂代替传统的无机酸催化剂。考察了离子交换树脂用量、反应温度对反应产率、活性氧含量的影响及溶剂对产品稳定性的影响。     

Ammoximation of methyl ethyl ketone with H2O2 and ammonia over TS‐1

The ammoximation of methyl ethyl ketone and hydrogen peroxide to form methyl ethyl ketoxime was studied over zeolites (TS‐1) in the temperature range 308–373 K. The reaction was carried out in a batch autoclave at autogenous pressure. The conversion of methyl ethyl ketone and the selectivity to methyl ethyl ketoxime can reach 99% and approximately 100%, respectively, and the by‐products were the small amounts of corresponding methyl ethyl ketazine and trace amounts of unidentified compounds. Important factors were the reaction temperature, solvents and slow addition of hydrogen peroxide. The molar ratio of NH₃ to ketone had no significant effect on the conversion of methyl ethyl ketone, but increase in the ratio of NH₃ to ketone had a beneficial effect on selectivity. Copyright © 2006 Society of Chemical Industry