丝光沸石-氧化铝双组元负载钼催化剂上的1-丁烯歧化反应

在固定床反应器上考察了氢型丝光沸石(HM)-氧化铝双组元负载MoO3催化剂上的1-丁烯歧化反应性能,通过氨程序升温脱附、X射线衍射和氢程序升温还原对样品进行了表征.实验结果表明,在110℃,0·1MPa,WHSV=1·5h-1及TOS=1h的反应条件下,MoO3没有歧化反应活性.Al2O3,HM-Al2O3和HM载体上只生成异构产物,并且载体酸性越强,异构产物越多.MoO3/HM几乎没有歧化活性,而MoO3/Al2O3催化剂上生成了一定量的歧化产物,且各产物收率相近.MoO3/HM-Al2O3具有最高的歧化活性,1-丁烯转化率为84·9%,丙烯和戊烯收率分别为28·5%和20·6%.催化剂本身的酸性和载体表面Mo物种存在状态是影响1-丁烯歧化制丙烯反应性能的两个关键因素.     

Ethylene/1-Butene Copolymerization over Heterogeneous Metallocene Catalyst

Summary: Nowadays, bimodal polyethylene obtained in a two step cascade process is a matter of intensive research in polyolefin field. In the second stage of this process, a high molecular weight ethylene-α-olefin copolymer is formed over the homopolymer produced in the first step. In this work, a study of reaction variables on this second step using an heterogeneous metallocene catalyst was carried out. The effect of reaction temperature (70–85 °C) and comonomer concentration (0–0.32 mol/l) was evaluated. Polymerization results showed that activity increases with temperature and 1-butene initial concentration. Moreover, higher comonomer concentrations and lower temperatures involve higher short chain branching (SCB). Copolymers characterization indicated that melt temperature and density values have a lineal decrease with the SCB content in the polymer, regardless of the reaction temperature. As well, for every temperature, higher comonomer concentrations do not seem to affect to molecular weight, whereas a decrease of crystallinity was observed, which may explain the increase of catalyst activity.     

Alternating Ethene/Propene Copolymerization with a Metallocene Catalyst

A small variation in the substituent R′ on the metallocene catalyst employed in the copolymerization of ethene and propene leads to a highly alternating (81–83%) structure ( 1 ) rather than a statistical copolymer. Such copolymers were until recently only accessible by hydrogenation of polyisoprene or 1,4-poly(pentadiene).     

新型非对称二醚给电子体丙烯聚合催化剂研究

1,3－丙二醚类化合物为给电子体合成的新一类复相Ziegler－Natta催化剂（Z-N催化剂）,其用于丙烯聚合时,在无需外加给电子体的情况下,可得到高活性的催化剂和高等规度的聚丙烯,催化剂的活性是以邻苯二甲酸二丁酯为内给电子体合成的Z-N催化剂的2～3倍,且得到聚丙烯的等规度大于95％[1-4]．由于1,3－丙二醚类化合物与载体的配位作用较强,不易与AlR3反应,因此在丙烯聚合时无需外给电子体,并能降低反应体系的复杂性,有利于研究活性中心结构和聚合机理［5-7]．以往研究均采用对称结构的 1,3－丙二醚类化合物作内给电子体［2-7],其结构如 Scheme 1 所示．本文采用一种新的     

Investigation of Propene Oligomerization Catalyst Series Derived from Complex of Ferric Sulfate and Nickel Sulfate

Some paper have reported that catalyt of NiSO₄/γAlO₃ has a very high oligomerization activity for propene, but the over tri oligomerization selectivity is very low^[1].The catalyt of Fe₂(SO₄)₃/γ-Al₂O₃ has a very high over trioligomerization selectivity, but oligomerization activity was lower then catalysis of NiSO₄/γ-Al₂O₃ for propene and stability of catalysis was not as good as catalysis of NiSO₄/γ-Al₂O₃^[2].In this paper the catalysis of Fe_(2/3)xNi_1-xSO₄-P₂O₅/γ-Al₂O₃ for propene oligomerization has been systematically studied, the effect of the activation method, the stability and reaction conditions on activity and selectivity were investigated. Fe_(2/3)xNi_1-xSO₄-P₂O₅/γ-Al₂O₃ catalysis was preparared by impregnation.The factors affecting catalyst performance for propene oligomerization are as follows.     

NiSO4／HY催化剂上丙烯齐聚反应研究

本文考察了ＮｉＳＯ_４／ＨＹ催化剂用于丙烯齐聚反应的催化性能，研究了镍含量、镍盐、焙烧温度以及反应条件对催化活性和选择性的影响，随镍含量增加，反应活性及二聚选择性都升高，镍含量为９一２０ｗｔ％时活性达最好，液体收率达９５ｗｔ％，随焙烧温度升高，二聚选择性不断升高。催化活性则在８２３Ｋ时有最大值。用吸附指示剂法测定了样品的酸分布，ＣＯ－ＴＰＤ法测定了暴露的Ｎｉ中心量，ＸＲＤ法测定了ＮｉＳＯ_４在ＨＹ上的分散阈值，讨论了它们与丙烯齐聚活性的关联。     

MCM-49分子筛催化剂上1-丁烯的骨架异构化反应

 采用动态和静态水热合成法合成了不同Si/Al比的MCM-49分子筛,并考察了合成分子筛对1-丁烯骨架异构化反应的催化性能. 结果表明,除目的产物异丁烯外,主要副产物为丙烯和戊烯,产物中没有检测到C6以上的副产物. 异丁烯收率随着反应温度的升高、分子筛晶粒的增大和1-丁烯分压的降低而升高. NH3-TPD 结果表明,随着分子筛Si/Al比的增加,分子筛的酸中心数减少,导致副产物选择性下降,异丁烯选择性升高. 根据反应结果讨论了异丁烯及副产物形成的机理.     

Two New On-Purpose Processes Enhancing Propene Production: Catalytic Cracking of C4 Alkenes to Propene and Metathesis of Ethene and 2-Butene to Propene

A brief review of the work carried out at Dalian Institute of Chemical Physics, Chinese Academy of Sciences for development of two new on-purpose processes enhancing propene production is presented. This includes the processes of catalytic cracking of C₄ alkenes to propene and metathesis of ethene and 2-butene to propene, by which the large amounts of the C₄ recourses from the petrochemical can be upgraded and the severity of demand for propene can be lessened.     

在SO42-/ZrO2 上苯与丙烯的烷基化反应

Super acidic catalyst SO42-/ZrO2 was prepared and characterized by XRD,IR,and Py-IR. Selectively catalytic gas phase flow reactions of benzene and propene over the catalyst were carried out in a made-to-measure high pressure flow reactor with a thermometer and a condenser. The benzene and propene were kept in pressure tanks at 8 : 1 ratio with N2 gas at 4. 0 MPa. The reactants were pumped into the quantifier where the pressure was maintained by N2 gas at 8. 0 MPa. They were then pumped into the reaction reactor using catalytic synthesis of isopropyl benzene. The collected liquid phase products were analyzed using GC-MS. Product analyses were carried out on SE-54. The effect of the preparative condition on the catalytic synthesis of isopropyl benzene over the catalysts has been tested. The result shows that the SO42-/ZrO2 can be used as a catalyst for the title reaction,and shows higher conversion（99.2%）for the propene and higher selectivity（93.3%）for the isopropyl benzene when the catalyst is preparated in some condition.     

Effect of Reaction Temperature and Pressure on the Metathesis Reaction between Ethene and 2-Butene to Propene on the WO3/Al2O3-HY Catalyst

Effect of reaction temperature and pressure on the metathesis reaction between ethene and 2-butene to propene was studied on the WO3/γ-Al2O3-HY catalyst. The activity is found to increase with elevated temperature and reaches a plateau at 150-240℃. After that, the activity undergoes a remarkable decrement at too high temperature. The effect of temperature is elucidated by the oxidation state of tungsten species. The evaluation results also indicate that the stability is dependent on this reaction parameter. Medium pressure (0.5-0.8 MPa) is favorable for stability, while atmospheric pressure or too high pressure (>1.0 MPa) deteriorates the stability. For explanation, UV Vis, FT-IR, O2-TPO, and TG techniques are used to characterize the spent catalysts.     

Catalyst Systems for Alkene Polymerization Based on Metallocene Complexes and Phenoxy Alumoxane with a Perfluorinated Phenyl Group

Summary: This paper describes the use of pentafluorophenoxy alumoxane, an oligomeric compound containing  Al(OC₆F₅) O units, as a cocatalyst for metallocene complexes in alkene polymerization reactions. Pentafluorophenoxy alumoxane is produced by two alternative routes. The first route consists of two consecutive reactions: (a) the reaction of AlR₃ with C₆F₅OH, and (b) the reaction of the product of the first step with water. The second route is the reaction between methylalumoxane and C₆F₅OH.

The synthesis of pentafluorophenoxy alumoxane oligomers.     

Kinetics of Coke Formation for the Reactions of Light Olefins Ethene, Propene and 1-Butene Over Ushy Zeolite

A simplified three-parameter model for the interpretation of the kinetic data of coke formation during transformation of light olefins is presented. This model has been applied to the transformation of ethene, propene and 1-butene over fresh and regenerated zeolite USHY at 623 K. The proposed model covers both the coverage of the acid sites and the autocatalytic growth of coke.     

六氟代戊二酮合镍/二异丁基氢化铝催化丙烯线性齐聚的研究

以1,1,1,5,5,5-六氟代戊二酮合镍(简称Ni(Hfacac)₂)和二异丁基氢化铝(简称(i-Bu)₂AlH)为催化剂使丙烯齐聚,丙烯二聚物的线性率为75-80%,研究了A₁/Ni[(i-Bu)₂AlH/Ni(Hfacac)₂摩尔比]、反应温度等因素对催化剂的活性、二聚物的线性率和二聚物的组成分布的影响,讨论了本反应体系的反应机理。     

Asymmetric Allylic Substitution Reactions with a Xylophos-Pd Catalyst

 The chiral diphosphine ligand xylophos (1) was tested as an auxiliary in palladium catalyzed allylic substitution reactions. Whereas its activity was found to be generally good only in the case of 1,3-diphenylprop-2-en-1-yl acetate, a fair level of asymmetric induction was achieved with sodium dimethyl malonate (83%ee) and benzylamine (66%ee) as nucleophiles.     

Asymmetric Allylic Substitution Reactions with a Xylophos-Pd Catalyst

Summary.  The chiral diphosphine ligand xylophos (1) was tested as an auxiliary in palladium catalyzed allylic substitution reactions. Whereas its activity was found to be generally good only in the case of 1,3-diphenylprop-2-en-1-yl acetate, a fair level of asymmetric induction was achieved with sodium dimethyl malonate (83%ee) and benzylamine (66%ee) as nucleophiles. Received June 13, 2000. Accepted July 3, 2000     

Copolymerization of Ethylene/1-Butene with Heterogeneous TiCl4/(α-Diimine)nickel(Ⅱ) Complex Combined Catalyst

The new type heterogeneous combined catalyst system TiCl4-(α-diimine)nickel(Ⅱ) complexes/MgCl2-SiO2/AlR3 was prepared. Ethylene and 1-butene were copolymerized with the catalysts in slurry phase. It was found that with combined catalyst, the copolymers with lower density and higher branched degree were obtained. 13CNMR results showed that in the obtained copolymers existed not only ethyl but also some other kinds of branches due to the fact that ethylene exhibits the behavior of oligomerization and copolymerization in-situ with combined catalysts.     

NO在Au／Al2O3催化剂上还原反应的TPD-MS研究

 考察了沉积－沉淀法制备的Au／Al2O3催化剂在O2存在下催化C3H6还原NO的反应，并用程序升温脱附－质谱（TPD－MS）手段研究了吸附于催化剂上的NO或NO－O2的脱附性能．结果表明：在O2存在的条件下，对于C3H6还原NO的反应，1％Au／Al2O3的催化活性最高，可于375℃左右使NO生成N2，转化率达60％．这与催化剂对所吸附NO的脱附性能密切相关，N2O可能是C3H6还原NO反应过程中产生的比较稳定的中间体．