A New Type of Polymer-Supported Metallocene Catalyst for Ethylene Polymerization

A new polymer-supported metallocene catalyst has been prepared, The polymer-supported metallocene displayed considerably high activity in ethylene polymerization, the highest being 3.62x10(7) gPE/molZr.h, the molecular weight of the polyethylene produced was Mn = 1.29x10(5). about 3-4 times those of corresponding homogeneous zirconocenes. The polymer-supported metallocene keeps the characteristics of homogeneous metallocene catalysts, and offers some features, such as adaptable to gas phase and slurry processes: easy to prepare in low cost: relatively high activity and lower MAO/Zr ratio; lower inorganic residues in the polyolefins as compared to cases of SiO2, Al2O3 or MgCl2; unitary active structure, no complex surface as with SiO2; good control of morphology of the resulting polymer.

Facile preparation of efficient oil-soluble MoS_2 hydrogenation nanocatalysts

Oil-soluble MoS2 nanoparticles with narrow size distribution have been synthesized by a facile composite-surfactants-aided-solvothermal process.The as-prepared nanoparticles can be directly used as hydrogenation nanocatalysts or as precursors to achieve efficient supported nanocatalysts.The surfaces of these nanoparticles are proposed to be encapsulated within a layer of organic modifiers,which are responsible for the enhancement of their solubility in organic solvents.The activated-carbon supported MoS2 nanocatalysts exhibit higher activity than the unsupported ones towards hydrogenation reactions of naphthalene,owing to the synergistic effects between nanoparticles and supports.The advantages of the present nanocatalysts,such as removal of conventional presulfiding requirements and reduction of nanoparticle aggregations,make them become promising applications in related petroleum chemical industry.

POLYMER-SUPPORTED RARE EARTH CATALYSTS FOR STYRENE POLYMERIZATION

The neodymium complex supported on styrene-maleic anhydride copolymer (SMA·Nd) has been prepared for the first time and found to be a highly effective catalyst for the polymerization of styrene. The SMA·Nd polymeric complex is characterized by IR and its catalytic activity, and the polymerization features have been investigated in comparison with that of the conventional Ziegler-Natta catalysts. When [Nd]=1×10^(-3) mol/L, [M]=5mol/L, Al/Nd=170(mol ratio) and CCl_4/Nd=50(mol ratio), the polymerization conversion of styrene gets to 51.6% in six hours, and the catalytic activity reaches 1852 gPS/gNd, which is much higher than that of conventional rare earth catalysts. The polymerization reaction has an induction period and shows some characteristics of chain polymerization. The polymerization rate is the first order with respect to the concentration of styrene monomer. Addition of FeCl_3 does not suppress the polymerization.

Synthesis of Polymer-Supported Heteronuclear Rhodium- Cobalt Bimetallic Carbonyl Cluster Catalysts and Their Hydroformylation Properties

Tetranuclear Rh-Co bimetallic cluster was synthesized and characterized by IR and XPS. The properties of the anchored catalysts, its stability and the ligand effect were also studied. The experimental results show that the optimal conditions for the hydroformylation of hexene-1 are as follows: the temperature is 80℃, reaction time 8 h, pressure 5. 88×105 Pa, and molar ratio of H2/CO 1. 2/1. 0. Functional groups attached to the donor atom(N) possess more or less some influence on the catalytic behavior. Compared with the homogeneous cluster, the polymer-supported bimetallic cluster is more stable. After the catalytic reaction, the structure of the anchored catalysts was not destroyed. X-ray photoelectron spectroscopy characterization indicates that there is a weak interaction between the polymer support and the active metals.

DESIGN OF POLYMER-SUPPORTEDCHIRAL CATALYSTS

Some structural factors to the design of polymer-supported Chiral Catalysts arediscussed, and some new approaches for designing of polymer-supported catalysts arereviewed in this paper

An Efficient Multifunctional Soluble Catalyst for Li-O_(2) Batteries

Aprotic lithium-oxygen(Li-O_(2))batteries have a high theoretical energy density,but they face challenges such as cathode blockage,high charge overpotential,and poor cycling stability.These are caused by sluggish reaction kinetics and severe parasitic reactions.Enhancing the performance of Li-O_(2) batteries necessitates the development of efficient catalysts.These catalysts not only augment both the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER)but also inhibit undesirable parasitic reactions.In this work,we demonstrated for the first time a multifunctional soluble catalyst of iridium(III)acetylacetonate(Ir(acac)_(3))that could speed up oxygen electrochemistry.Ir(acac)_(3) regulated the ORR pathway and the reactivity of superoxide radical species by forming a reversible intermediate complex(Ir(acac)_(3)-O_(2)^(−)).During charging,Ir(acac)_(3) acted as a redox mediator and aided in Li_(2)O_(2) decomposition by reacting with superoxide intermediates.Moreover,as demonstrated by operando UV-visible spectroscopy,the lower charge potential significantly reduced the generation of highly reactive singlet oxygen(^(1)O_(2))intermediates.As a result,the Ir(acac)_(3)-mediated Li-O_(2) battery showed low overpotential,large capacity,and stable cyclability.This study offers a new approach to achieving efficient Li-O_(2) batteries and provides an opportunity to suppress parasitic reactions.

Preparation of fructone catalyzed by water-soluble Brφnsted acid ionic liquids

Fructone （2-methyl-2-ethylacetoacetate-1, 3-dioxolane）, a flavouring material, has been synthesized from ethyl acetoacetate and glycol using five water-soluble Brφnsted acid ionic liquids as catalysts for the first time. The used Brφnsted acid ionic liquids include [Hmim]Tfa, [Hmim]Tsa, [Hmim]BF4, [Bmim]HSO4, [Bmim]H2P04, and [Hmim]BF4 showed the highest catalytic activity for the preparation of fructone. After reaction, the product could be isolated from the reaction system automatically, and the ionic liquid could be directly reused without dehydration.

Synthesis and Catalytic Activities of Polymer-Supported Neodymium Complexes——Polymers Containing Thiol and Sulphoxide

The neodymium complexes with crosslinked polystyrene containing -CH2SH and -CH2SOCH3 groups, P-CH2SH . NdCl3 and P-CH2SOCH3. NdCl3, were prepared. P-CH2SH . NdCl3 shows no catalytic activity for butadiene polymerization, while P-CH2SOCH3. NdCl3 can catalyze the polymerization of butadiene. The content of cis-1,4-polybutadiene is more than 95%.

SYNTHESIS AND CATALYTIC PROPERTY OF POLYMER-SUPPORTED Fe-Co HETEROTETRAMETALLIC CLUSTERS

Four polymer-supported Fe-Co tetrametallic clusters have been prepared by ion exchange and ligand exchange. Their structures were characterized by IR, UV/visible diffuse reflectance spectra and elemental analysis, and by analogy with the reference cluster PhCH_2NMe_3FeCo_3 (CO)_2 . The four heterogenous clusters were efficient catalysts in the hydroformylation of 1-hexene, turnover numbers amounted to 823 — 924 with the yield of 83.2—92.4% heptyl aldehydes and ratios of normal aldehyde to iso-aldehyde of 1.2—1.6, they are facilitated forming the normal aldehyde in comparison with the homogeneous analogue. For the polymer-supported clusters prepared by ion exchange, the polymer-cation parts had no obvious effect on the activity of the cluster anion. The polymer-phosphine substituted cluster prepared by ligand exchange was more stable than the clusters preparedby ion exchange.

硫化温度对油溶性催化剂硫化程度的影响

针对含硫和不含硫的2种油溶性催化剂在不同硫化温度下进行预硫化处理,采用元素分析、XRD、HRTEM、XPS等手段对处理后的催化剂进行表征,并以二苯并噻吩作为模型化合物,考察不同硫化温度催化剂对二苯并噻吩的脱硫活性和加氢脱硫(HDS)反应路径的影响。结果表明,随着硫化温度的升高,2种油溶性催化剂的Mo^(4+)含量均增加,硫化程度加深,MoS_(2)活性相的XRD特征峰呈现出逐渐尖锐和明显的趋势,且MoS_(2)条纹的长度及堆积层数逐渐增加。在HDS反应性能评价中,2种油溶性催化剂对二苯并噻吩的脱硫性能均以直接脱硫(DDS)路径为主,且随着硫化温度的增加,HDS路径选择性呈现下降趋势。其中,含硫的油溶性催化剂随着硫化温度的升高,其活性呈现下降趋势;而不含硫的油溶性催化剂在硫化温度为320℃时表现出最高的催化活性。

硫化剂结构对油溶性Mo基催化剂硫化的影响

选取了5种不同结构的硫化物作为硫化剂,以油溶性有机钼催化剂MACC为研究对象进行催化剂硫化试验,考察硫化剂结构对催化剂硫化形成的活性中心结构、形貌、分布以及粒度的影响。结果表明,试验条件下,二苯并噻吩和甲硫醚很难与催化剂发生硫化反应生成活性中心,十二硫醇、二甲基二硫醚(DMDS)以及升华硫均可与催化剂反应生成活性中心,且十二硫醇作为硫化剂时得到的活性相MoS 2条纹数更少、分散度更高,DMDS和升华硫作为硫化剂时得到的样品硫化度更高(约90%)。模拟MACC催化剂在原料混合罐工况下发生硫化反应,结果表明,二苯并噻吩不能实现MACC催化剂硫化,而升华硫在混合罐条件下可达到较高的硫化度。

重质油催化裂化用催化剂的研制及性能评价

催化裂化是提高重质油资源利用效率的一种常用加工技术,为了提高重质油资源催化裂化的效率,以Ni(NO_(3))_(2)、FeCl_(3)和脂肪酸为主要原料,制备出一种适用于重质油催化裂化的新型油溶性催化剂FN-1,并采用小型固定流化床装置考察了不同因素对重质油催化裂化反应的影响。实验结果表明,随反应温度的升高,重质油转化率逐渐增大,生成的汽油成分中烯烃和芳烃含量逐渐增大;随剂油质量比的逐渐增大,重质油转化率逐渐增大,汽油中异构烷烃和烯烃的含量逐渐减小,芳烃含量逐渐增大;随质量空速的逐渐增大,重质油转化率逐渐减小,汽油中异构烷烃和烯烃的含量逐渐增大,芳烃含量逐渐减小,但变化的幅度比较小。当重质油催化裂化的反应温度为520℃、剂油质量比为6、质量空速为15h-1时,重质油的转化率可以达到95.38%,催化裂化效果较好。

DEVELOPMENT OF A CATALYST FOR SOLUTION OF POLY(VINYL ALCOHOL) IN NON-AQUEOUS MEDIUM

Chloro ethane dimethyl sulfoxide,C_2H_5Cl·DMSO(ECI·DMSO)was prepared by interaction of acrylic acid with conc.Hydrochloric acid in dimethyl sulfoxide(DMSO)and subsequent decarboxylation with H_2O_2 solution.The formation of the compound was confirmed by spectral and analytical methods;the molecular weight was determined by cryoscopic method.The solubility of poly(vinyl alcohol)(PVA)in different solvents or mixed solvents at 40℃,50℃and 60℃temperature in the presence of 0.01% of EC1·-DMSO was determined.It tu...

HYDROGENATION ACTIVITY OF ADSORBINGRESIN SUPPORTED PALLADIUM—METALLIC OXIDE CATALYSTS

Hydrogenations for olefinic double bonds catalyted by the Pd-Fe2O3/D3520 resin and Pd-Bi2O3/D3520 resin were reported. These catatysts were characterized by IR spectra and XPS methods. The XPS investigation indicated that the-electron transfer from Fe atom in Fe2O3 to Pd, enhanced the hy-drogenation activity of the catalysts,and Bi2O3 drew electrons from Pd, leading to the lowering of the hydrogenation rate. When Pd/Bi atom ratio = 1, the hydrogenation was inhibited entirely. The IR spectra of resin 1)3520 showed no significant changes when Pd and the metallic oxides were supported on the polymer particles. That indicates that there are no obvious inter-actions between Pd (or metallic oxides) and supporter. Finally , a possible hydrogenation mechanism ,was also supposed.

A Novel Complex of Pyridinium Polystyrylsulfonate with Fluoboric Acid as a Catalyst for Acetalization of Benzaldehyde with n-Butanol

A new complex (1) was prepared by mixing pyridinium polystyrylsulfonate resin and aqueous fluoboric acid, followed by being dehydrated. 1 can be used as an acidic catalyst for the acetalization of benzaldehyde with n-butanol with a highly catalytic activity. The characterization and reusability of 1 are discussed.

BICENTRAL POLYMER SUPPORTED PHASE TRANSFER CATALYST POLYSTYRENE－SUPPORTED POLYETHYLENE GLYCOL AND PYRIDINIUM SALT

A bicentral polymer-supported Phase transfer catalyst, polystpyne-suPPorted polyethylene glycol and Pyridinium salt (PS-Py-PEG-400),synthesized with ohloromethylated polystyrene as supporter on which PEG and Pyridinium salt were immobilized successively. Its catalytic activity was tested for the reauction of solid potassium acetate and benzyl bromide by GC analysis. It was found that the bicentral catalyst performed higher activity than the monocentral PS-PEG-400 and PS-Py.

2,2′-二苯甲酰氨基二苯基二硫化物/氧化锌催化剂降低废旧胶粉脱硫温度的研究

用环烷油作为脱硫溶剂,研究了由2,2′-二苯甲酰氨基二苯二硫化物(DBD)和氧化锌(ZNO)按比例混合而成的催化剂DZ对胶粉脱硫温度的影响,在此基础上,以再生胶在三氯乙烯溶液中的溶解度为核心指标,进一步考虑了催化剂掺量、脱硫时间、胶油比的影响,确定了制备低温脱硫胶粉的最优工艺参数。通过扫描电子显微镜、傅里叶红外光谱检测揭示胶粉低温脱硫的机理和微观形貌。结果表明,催化剂DZ对胶粉脱硫起着积极的影响,经过低温脱硫处理的再生胶,粗糙度降低,表面的“凹槽”结构更加明显,能够被更好地应用到工程中;将胶粉脱硫温度降到160℃的同时,再生胶溶解度能够达到76.9%,接近传统动态脱硫法制备的再生胶溶解度,表明降低脱硫温度几乎不会对胶粉的溶解度产生不利影响;低温脱硫胶粉的制备参数可确定为:胶粉和环烷油的质量比为4∶6,催化剂DZ掺量为3%,搅拌速率为450 r/min,脱硫时间为2 h,脱硫温度为160℃。

甲醇低压羰基合成醋酸中三碘化铑溶解率提升的研究

甲醇低压羰基合成醋酸工艺已经成为当前最成熟的生产技术,在醋酸产能总体过剩的市场行情下,降低生产成本将尤为重要。其中,三碘化铑催化剂占生产成本中较大一部分,分析了甲醇低压羰基合成醋酸中三碘化铑反应机理,并探索三碘化铑溶解率的影响因素,从而确定最优工艺参数。探索了一种三碘化铑溶解率提升的新工艺,操作简单,溶解率高,可节约醋酸生产装置开车时间,有效提升醋酸装置负荷提升速度,对醋酸生产技术的提升具有指导意义。

SYNTHESIS, CHARACTERIZATION AND SPECTROSCOPIC INVESTIGATION OF PYRAZINOPORPHYRAZINE NETWORK POLYMER-SUPPORTED METAL (Ⅱ)-BASED CATALYSTS

Chloranil through condensation reaction with vicinal diamine such as diaminomaleonitrile produced heterocyclic monomer, p-benzoquinonebis[2,3-b; 2＇,3＇-b＇]pyrazine-5,6-dinitrile. The tetranitrile monomer was cyclo-tetramerised using lithium/pentanol and acetic acid affording the corresponding tetrap-benzoquinone bis[2,3-b; 2＇,3＇-b＇]pyrazinoporphyrazine）]- based network polymer （2H-Pz）. The tetranitril monomer was cyclo-tetramerised using metal salt and quinoline affording the corresponding porphyrazinato-metal II-based network polymers （M-Pz）, M = Co, Ni or Cu. Elemental analytical results, IR and NMR spectral data of the prepared molecules are consistent with their assigned formulations. Molecular masses and metal contents of the synthesized polymers proved to be of high molecular masses which confirm the efficiency of tetramerization polymerization and complexation reactions. The prepared pyrazinoporphyrazines were used as efficient catalysts for the oxidation of thiophenol and benzylthiol to their disulfides in the presence of air atmosphere. The results of oxidation of thiophenol and benzylthiol show that after 15 min the maximum yield of the corresponding disulfides reached 95%, 91%, respectively.