组合催化在石油化工催化开发中的应用

概述了组合催化的基本原理及实验装置,主要介绍了组合催化在丙烯环氧化制环氧丙烷、甲醇与甲苯侧链烷基化制苯乙烯、丁二烯制四氢呋喃、乙烷/丙烷氧化脱氢制乙烯/丙烯等石油化工过程催化剂研发中的应用,指出组合催化将是未来发现新催化材料及新催化过程的有效手段。     

茂金属烯烃聚合催化剂Ⅱ.丙烯茂金属催化剂结构对称性和立体选择性的关系

介绍了茂金属催化剂的研究进展及茂金属催化剂在乙烯、丙烯和苯乙烯等聚合反应中的应用。     

茂金属烯烃聚合催化剂Ⅰ.聚合机理及助催化体系

介绍了茂金属催化剂的研究进展及茂金属催化剂在乙烯、丙烯和苯乙烯等聚合反应中的应用。     

茂金属烯烃聚合催化剂Ⅲ.乙烯聚合茂金属催化剂结构和配体对聚合反应的影响

介绍了茂金属催化剂的研究进展及茂金属催化剂在乙烯，丙烯和苯乙烯等聚合反应中的应用。     

Production and operation of dehydrogenation catalysts

The paper considers the production and exploitation of dehydrogenation catalysts for the production of isobutylene, propylene, isoprene, styrene, α-methylstyrene, and divinylbenzene. The recent developments of the JSC Research Institute Yarsintez on this subject are proposed.     

Polymer-supported molybdenum and vanadium catalysts for epoxidation of alkenes by alkyl hydroperoxides

Polymer-supported molybdenum and vanadium catalysts were synthesized using gel-type crosslinked copolymers with microheterogeneous structure. The supports were composed of inert ethylene–propylene rubber and crosslinked high molecular weight poly(ethylene oxide) matrices and polymeric ligands grafted or forming interpenetrating networks: poly(acrylic acid), poly(methacrylic acid), poly(4-vinylpyridine), and polyvinyl alcohol. Catalytic activity and selectivity of some of these complexes were tested in epoxidation of styrene by ethylbenzene hydroperoxide. Molybdenyl cations are strongly coordinated with pyridine-containing copolymers giving catalysts of high activity and selectivity. They provide conversion and selectivity above 70%. Because of the microheterogeneous mosaic-like structure of the supports, better accessibility of the active sites is achieved.     

茂钛催化剂合成及苯乙烯间规聚合

介绍了茂钛催化剂ＣｐＴｉ（ＯＰｈ）３（Ｃｐ为环戊二烯基）的合成。使用ＣｐＴｉ（ＯＰｈ）３／ＭＡＯ均相催化体系,研究了工艺条件对苯乙烯间规聚合的影响。初步探讨了以带有反应性功能基团的聚苯乙烯为载体,负载ＣｐＴｉＣｌ３后进行的苯乙烯间规聚合。同时采用了不同配体的ＣｐＴｉ（ＯＲ）３催化剂用于苯乙与乙烯或丙烯共聚合,得到的共聚产物是一类应用前景良好的工程塑料。     

制备全系列聚烯烃材料的高性能单活性中心催化剂研究进展

高性能单活性中心催化剂的发展给聚烯烃分子链结构的设计与"精确调控"提供了强大的工具,然而设计、制备和优化耐高温多功能催化剂成为制备高性能、高附加值聚烯烃产品的核心。本文回顾了全系列聚烯烃材料的种类,热性能和材料类型与共单体含量之间的关系。重点综述了:①改进型CGC-Ti、半茂钛、非茂铪(锆)等耐高温乙烯/α-烯烃共聚催化剂;②半茂钛、非茂钛等乙烯/(苯乙烯、降冰片烯)系列共聚催化剂;③优化型C2/C1-对称茂锆、耐高温非茂铪等高立构丙烯均聚和等规丙烯-乙烯系列共聚催化剂;④含杂环的C2/C1-对称茂锆高等规1-丁烯本体溶液聚合催化剂。与此同时,对这些催化剂的性能及其相应产物的链结构进行了详细地讨论。最后指出,优化耐高温等规型非茂铪和含杂环或杂原子的C2/C1-对称茂锆以及间规型C1-对称茂锆等多功能催化剂是今后的研究重点。     

Polymeric proton conducting systems based on commercial elastomers. II. Synthesis and microstructural characterization of films based on HSBR/EPDM/PP/PS/silica

This article reports on the synthesis and structural characterization of films containing hydrogenated poly(butadiene‐styrene) block copolymer/ethylene‐propylene terpolymer/polypropylene, hydrogenated poly(butadiene‐styrene) block copolymer/ethylene‐propylene terpolymer/polystyrene, and hydrogenated poly(butadiene‐styrene block copolymer/ethylene‐propylene terpolymer/silica) crosslinked with peroxides and heterogeneously sulfonated. Sulfonation of the different polymeric systems gives rise to materials with high proton conductivity and great dimensional stability, suited for application in a variety of electronic devices. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2394–2402, 2004     

FI Catalysts: A New Family of High Performance Catalysts for Olefin Polymerization

This paper reviews a new family of olefin polymerization catalysts. The catalysts, named FI catalysts, are based on non‐symmetrical phenoxyimine chelate ligands combined with group 4 transition metals and were developed using “ligand‐oriented catalyst design”. FI catalysts display very high ethylene polymerization activities under mild conditions. The highest activity exhibited by a zirconium FI catalyst reached an astonishing catalyst turnover frequency (TOF) of 64,900 s ^–1 atm ^–1, which is two orders of magnitude greater than that seen with Cp₂ZrCl₂ under the same conditions. In addition, titanium FI catalysts with fluorinated ligands promote exceptionally high‐speed, living ethylene polymerization and can produce monodisperse high molecular weight polyethylenes (M_w/M_n<1.2, max. M_n>400,000) at 50 °C. The maximum TOF, 24,500 min ^–1 atm ^–1, is three orders of magnitude greater than those for known living ethylene polymerization catalysts. Moreover, the fluorinated FI catalysts promote stereospecific room‐temperature living polymerization of propylene to provide highly syndiotactic monodisperse polypropylene (max. [rr] 98%). The versatility of the FI catalysts allows for the creation of new polymers which are difficult or impossible to prepare using group 4 metallocene catalysts. For example, it is possible to prepare low molecular weight (M_v∼10³) polyethylene or poly(ethylene‐co‐propylene) with olefinic end groups, ultra‐high molecular weight polyethylene or poly(ethylene‐co‐propylene), high molecular weight poly(1‐hexene) with atactic structures including frequent regioerrors, monodisperse poly(ethylene‐co‐propylene) with various propylene contents, and a number of polyolefin block copolymers [e.g., polyethylene‐b‐poly(ethylene‐co‐propylene), syndiotactic polypropylene‐b‐poly(ethylene‐co‐propylene), polyethylene‐b‐poly(ethylene‐co‐propylene)‐b‐syndiotactic polypropylene]. These unique polymers are anticipated to possess novel material properties and uses.     

Kinetics of the reaction of propylene oxide with carbon dioxide in the presence of tetrasubstituted ammonium and phosphonium halogenides

Reactions of alkylene oxides with carbon dioxide underlie the industrial technology of ethylene- and propylene carbonates. Looking for new catalytic systems for these processes remains of interest due to the possibility of creating a new energy-saving process for the production of ethylene and propylene glycols. This work is aimed at comparing the catalytic activity of halogenides in the reaction of propylene oxide (PO) and carbon dioxide in the presence of tetrasubstituted ammonium and phosphonium halogenides, and evaluating the feasibility of using them in designing industrial technologies for the production of alkylene carbonates and glycols as active catalytic systems. Triphenylphosphine halogenides have been shown to possess high catalytic activity as compared to triethanolamine-based analogs. In terms of efficiency, triphenylphosphonium bromides are as good as the familiar catalysts based on potassium iodide. The high activity of these catalysts in the reaction for propylene carbonate (PC) production and their good solubility in the reaction medium allow us to propose them for the development of industrial technology for the subsequent production of alkyl carbonates and alkylene glycols.     

Direct Oxidation of Propylene to Propylene Oxide with Molecular Oxygen: A Review

The direct oxidation of propylene to propylene oxide (PO) using molecular oxygen has many advantages over existing chlorohydrin and hydroperoxide process, which produce side products and require complex purification schemes. Recent advances in liquid-phase and gas-phase catalytic oxidation of propylene in the presence of only molecular oxygen as oxidant and in absence of reducing agents are summarized. Liquid-phase PO processes involving soluble or insoluble Mo, W, or V catalysts have been reported which provide moderate conversions and selectivities, but these likely involve autoxidation by homogeneous chain reactions. Gas-phase PO catalysts have been mostly Ag-, Cu-, or TiO₂-based substances, although other compositions such as Au-, MoO₃-, Bi-based catalysts and photocatalysts have also been suggested as possibilities. The Ag catalysts differ from those used for ethylene oxide production in having high Ag contents and numerous additives. The additives are solid-phase alkali metals, alkaline earth metals, and halogens, with the most common substances being NaCl and CaCO₃. Nitrogen oxides in the form of gas-phase species or nitrates have also been found to be effective in enhancing PO production. Direct epoxidation by surface nitrates is a possibility. Titania catalysts supported on silicates have also been reported. These have higher PO selectivities at high conversion than silver catalysts.     

Copolymerization of ethylene and propylene catalyzed by novel magnesium chloride supported,vanadium‐based catalysts

Two novel magnesium chloride supported, vanadium‐based Ziegler–Natta catalysts with 9,9‐bis(methoxymethyl)fluorene and di‐i‐butyl phthalate as internal donors were prepared and used in the copolymerization of ethylene and propylene. The catalytic behaviors of these catalysts were investigated and compared with those of traditional magnesium chloride supported, vanadium‐based catalysts without internal donors. Differential scanning calorimetry, gel permeation chromatography, and ¹³C‐NMR spectroscopy analysis were performed to characterize the melting temperatures, molecular weights, and molecular weight distributions as well as structures and compositions of the products. The copolymerization kinetic results indicated that the novel catalyst with 9,9‐bis(methoxymethyl)fluorene as an internal donor had the highest catalytic activity and optimal kinetic behavior in ethylene–propylene copolymerization with an ethylene/propylene molar ratio of 44/56. Low‐crystallinity and high‐molecular‐weight copolymers were obtained with these novel magnesium chloride supported, vanadium‐based catalysts. The reactivity ratio data indicated that the catalytic systems had a tendency to produce random ethylene–propylene copolymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of ethylene/styrene copolymers produced by metallocene catalysts

Ethylene/styrene copolymers were synthesized under constant polymerization conditions using six different metallocene catalysts activated with methylaluminoxane. For all the catalysts used, the activity and molecular weight of the copolymers produced decreased with the amount of styrene in the reactor feed, but the styrene content of the copolymers increased. Catalysts with carbon bridges and bulky ligands gave rise to copolymers with higher styrene content. As a result of the increased styrene content of the copolymer, the melting temperature decreased. This effect was ascribed to a decrease in the crystallinity of the copolymers. It was also found that lamellar thickness could be significantly diminished by the incorporation of comonomers. The copolymers showed a broad spectrum of mechanical properties as a function of the comonomer ratio. At low styrene contents, they behaved like typical semicrystalline thermoplastics, and at higher styrene contents, they exhibited the properties typical of elastomers. Of the catalysts tested, [rac‐ethylenebis(4,5,6,7‐tetrahydro‐1‐indenyl)]zirconium dichloride emerged as the most promising for the production of ethylene/styrene copolymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3420–3429, 2006     

Influence of the catalyst matrix structure of the supported Ziegler-Natta catalysts on the homo- and copolymerization of olefins

The vanadium catalytic complexes immobilized on the same support (aluminium hydroxide, AH) and distinguished by structure and composition have been compared for ethylene and propylene homo- and copolymerization to find relationship between the polymerization activity, copolymerization relative reactivity of comonomers and the supported catalyst structure. The catalytic complexes of vanadium with supported aluminoxanes (II) and catalysts with dispersed solid phase of vanadium compounds on the support surface (III) are more active than catalyst (I) in which vanadium has the covalent bond with surface of support. The relative reactivity of comonomers in copolymerization also depends on type of supported catalyst. The catalysts III unlike I and II can produce the ethylene and propylene copolymers with high content of propylene. The promoting effect of propylene on ethylene polymerization rate takes place only in the presence of catalysts III. Received: 2 October 1996/Revised: 17 January 1997/Accepted: 23 January 1997     

Identification of rubber polymers in rubber blends

Abstract

Solid phase extraction (SPE) was used to separate pyrolysates of rubber blends. Then each rubber polymer in rubber blends was identified, based on interpreting infrared spectrum of separated pyrolysates. By using this method, nature–ethylene–propylene, ethylene–propylene–silicone, butyl–styrene–butadiene and ethylene–propylene–butadiene–acrylonitrile rubber blends were analysed. The analytical results show that each characteristic pyrolysate of polymer in rubber blend pyrolysate can be separated by SPE. The method for identification of rubber polymers in rubber blends by infrared coupled with SPE is flexible, rapid and low cost, compared with the method by pyrolysis gas chromatography coupled with infrared spectroscopy or mass spectroscopy.     

Selective hydrogenolysis of glycerol to propylene glycol on Cu–ZnO catalysts

Hydrogenolysis of biomass-derived glycerol is an alternative route to sustainable production of propylene glycol. Cu–ZnO catalysts were prepared by coprecipitation with a range of Cu/Zn atomic ratio (0.6–2.0) and examined in glycerol hydrogenolysis to propylene glycol at 453–513 K and 4.2 MPa H₂. These catalysts possess acid and hydrogenation sites required for bifunctional glycerol reaction pathways, most likely involving glycerol dehydration to acetol and glycidol intermediates on acidic ZnO surfaces, and their subsequent hydrogenation on Cu surfaces. Glycerol hydrogenolysis conversions and selectivities depend on Cu and ZnO particle sizes. Smaller ZnO and Cu domains led to higher conversions and propylene glycol selectivities, respectively. A high propylene glycol selectivity (83.6%), with a 94.3% combined selectivity to propylene glycol and ethylene glycol (also a valuable product) was achieved at 22.5% glycerol conversion at 473 K on Cu–ZnO (Cu/Zn = 1.0) with relatively small Cu particles. Reaction temperature effects showed that optimal temperatures (e.g. 493 K) are required for high propylene glycol selectivities, probably as a result of optimized adsorption and transformation of the reaction intermediates on the catalyst surfaces. These preliminary results provide guidance for the synthesis of more efficient Cu–ZnO catalysts and for the optimization of reaction parameters for selective glycerol hydrogenolysis to produce propylene glycol.     

碳二前脱丙烷前加氢催化剂工艺条件试验

采用浸渍法制备Pd-Ag/α-Al2O3催化剂,采用碳二前脱丙烷前加氢工艺系统考察反应器入口温度、空速和反应压力对催化剂性能的影响。结果表明,随着反应器入口温度升高,乙炔和丙炔+丙二烯转化率提高,乙烯选择性提高至一定值后趋于稳定,丙烯选择性波动不大,正丁烯生成量增加,较为适宜的反应器入口温度为(60~70)℃;随着空速升高,乙炔和丙炔+丙二烯转化率降低,乙烯选择性提高,丙烯选择性变化不大,正丁烯生成量降低,较为适宜的空速为(12 000~14 000)h-1;随着反应压力升高,乙炔转化率和丙炔+丙二烯转化率略增,乙烯选择性降低,较为适宜的反应压力为3.6 MPa。     

我国环氧丙烷的生产与市场分析

评述了环氧丙烷的生产工艺,分析了国内环氧丙烷、苯乙烯及其主要衍生产品的生产、消费和贸易情况。指出我国环 氧丙烷衍生产品的发展严重滞后,主要衍生产品聚醚的品种单一,在精细化工和表面活性剂方面应用很少;第二大衍生产品丙 二醇已停产。建议我国环氧丙烷生产企业应以市场为导向有序生产,理性竞争。     

催化裂化制乙烯、丙烯催化剂的研究进展

对催化裂化多产乙烯,丙烯催化剂的研究进展进行了概述,分析了金属氧化物催化剂和分子筛催化剂的反应特性、研发依据及应用情况.并展望了多产乙烯、丙烯催化剂的发展方向.