Skeletal Amorphous Nickel Based Alloy Catalysts and Magnetically Stabilized Bed Hydrogenation Technology

Looking toward 21 century, smaller, cleaner and more energy-efficient technology will be an important trend in the development of chemical industry. In light of the new process requirements, a number of technology breakthroughs have occurred. One of these discoveries, the magnetically stabilized bed (MSB), has been proven a powerful process for intensification. Since its initial research in the late 1980’s at Research Institute of Petroleum Processing (RIPP), the MSB technology and rela…     

微波消解-电感耦合等离子体原子发射光谱法测定镍基合金中铁、铌和钼的含量

镍基合金具有良好的耐高温、耐腐蚀特性[1],其中,以UNS N06625为代表的镍铬钼体系合金具有良好的加工性和焊接性[2]。镍基625系列的激光焊粉末、焊条及焊丝的焊接熔敷金属具有和UNS N06625相似的性质,在多种介质中均表现良好的耐腐蚀性,广泛应用于航空航天、石油化工、船舶制造等领域[3],其主要化学成分见表1。     

ICP—AES法测定镍基合金中合金元素含量

ＩＣＰ ＡＥＳ法灵敏度高 ,线性范围宽 ,并同时测定多种元素 ,已成为现代分析测试技术中一个重要的检测手段 ,广泛地应用在各个领域。由于核电用材镍基合金焊丝及焊带是以镍作为基体 ,硅、锰、铬、铁等元素含量较高 ,而钛、铝的含量却很低 ,其基体较复杂 ,各元素含量相差又较悬殊 ,所以给分析工作带来困难。本文采用ＰＳ 6型ＩＣＰ多道真空光谱仪 ,通过对镍基合金试样的溶解方法、等离子体发射光谱仪的工作参数、共存元素的干扰、离峰分析校正等进行了研究 ,从而制定了相应准确有效的方法 ,解决了生产检测的困难 ,结果满意[1] 。1　试验部分…     

氢氧化镍微米棒的合成和表征

以NiCl₂为镍源,乙二醇(EG)为溶剂,采用溶剂热法成功地制备了β-Ni(OH)₂微米棒,制备方法简单、易行。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、傅立叶红外光谱(FTIR)和电感耦合等离子直读光谱仪(ICP)对产物的形貌和物质结构进行了表征,证实了反应中间体是Ni-EG配合物。利用扫描电子显微镜(SEM)考察了实验参数,如聚乙二醇200浓度、反应温度和反应时间,对产物形貌的影响,结果表明一维棒状β-Ni(OH)₂的形成经历了溶解-再结晶的过程。Ni-EG配合物经退火处理,可以得到由纳米线自组装的NiO微米管。     

铂基Pb-Sb表面合金电催化剂的制备与结构表征

通过电化学方法,在玻碳载体表面制备以Pt、Pb、Sb为主要成分的铂基Pb Sb表面合金电催化剂.运用电化学循环伏安、石英晶体微天平（EQCM）和扫描隧道显微镜（STM）技术对催化剂电极进行表征.结果表明：酸性溶液中在所制备的表面合金电极上,析氢起始电位负移至－0.45 V,表面合金的起始氧化电位为0.15 V,其稳定性明显高于电催化还原中常用的铅、锑等金属电极.通过EQCM研究表面合金电极的形成过程,结合STM观察和XPS深度剖析,确定电催化剂表面是由粒度均匀的纳米颗粒构成的表面合金层.     

几种对称镍卟啉配合物的合成、表征和电化学性质

卟啉试剂是一类重要的离子配位显色剂,在生物体中具有重要作用．作为自然界存在的金属卟啉之一,镍卟啉的电化学研究具有化学和生物学意义．四对羟基苯基卟啉合成已有不少报道［１,２］,但产率较低,只有１０％左右．Ｌｉｎｄｓｅｙ等发现用ＢＦ３作催化剂,在ＣＨ２Ｃ...     

EDTA滴定法直接测定镍铁中镍量

测定常量镍常采用丁二酮肟重量法或氨性分离-EDTA滴定法.但两者分析流程均较长而不适于快速分析.EDTA滴定法测定镍的应用已较为广泛[1-3].本工作采用氟化钠掩蔽铁、铝,六偏磷酸钠掩蔽锰,在过量的EDTA存在下,于pH约4.6的乙酸-乙酸盐缓冲介质中,以PAN作指示剂,用硫酸铜标准溶液返滴定过量EDTA的方法直接测定镍铁中镍.方法简便,分析结果满意.     

Nickel Complexes Based on Salicylaldehyde-imine Ligands: Synthesis,Characterization and Catalytic Oligomerization of Ethylene

A series of nickel complexes {NOON^R}Ni(A:R=Me; B:R=t-Bu; C:R=OMe) based on salicylaldehyde-imine ligands was synthesized through Schiff base condensation and metal complexation reaction. Upon activation with methylaluminoxane(MAO), nickel complexes A-C all exhibited good catalytic activity[turnover frequency=5.2×10⁵-16.3×10⁵ g/(mol Ni·h)] and oligomer selectivity(above 85%, mass fraction) in ethylene oligomerization. In addition, C₈-C₁₂ olefins occupied an important proportion in the products of oligomers. Under the conditions of 4.0 MPa, 25℃ and Al/Ni molar ratio of 275, the catalytic selectivity of A/MAO system toward C₈-C₁₂ was about 30.1%(mass fraction), and the content of C₈-C₁₂ α-olefins was consistently above 70%. Furthermore, besides the ligand environment, the catalytic properties of A-C were substantially affected by experimental parameters, such as the reaction pressure, reaction temperature and Al/Ni ratio.     

Synthesis,Characterization and Ethylene Oligomerization Behavior of Neutral Nickel Complexes Bearing N‐Fluorinated Phenyl Salicylaldiminato Chelate Ligands

A series of neutral nickel complexes featuring N‐fluorinated phenyl salicylaldiminato chelate ligands was synthesized, and the novel molecular structure of complex C14 was further confirmed by X‐ray crystallographic analysis. The neutral nickel complexes showed high activity up to 9.96×10⁵ g oligomers/(mol Ni·h) and high selectivity of C₆ in catalyzing ethylene oligomerization using methylaluminoxane (MAO) as cocatalyst. It was observed that the strong electron‐withdrawing effect of the fluorinated salicylaldiminato ligand was able to significantly increase the catalytic activity for oligomerization of ethylene. In addition, the influence of reaction parameters such as Al/Ni molar ratio, reaction temperature, a variety of cocatalyst and ethylene pressure on catalytic activity was investigated.     

Synthesis and Characterization of Amphiphilic PEG Based Polymers and Their Self Assembling Behavior

Sixteen amphiphilic polymers were synthesized using poly(ethylene glycols) (PEGs) of different molecular weights, viz. 1000, 1500, 2000 and 4000 as hydrophilic block and linkers namely azelaic acid, suberic acid, terephthalic acid and glycolic acid as hydrophobic block in the presence of catalyst conc. H₂SO₄ out of which four with glycolic acid as linker are new. Synthesized polymers were characterized by using ¹H-NMR, ¹³C-NMR and IR spectroscopy. Micellar sizes of the polymers were determined using Dynamic Light Scattering (DLS) technique which ranged from 32.1–262.0 nm and confirmed by Transmission Electron Microscope (TEM) analysis. Molecular weights were determined using HORIBA SZ-100 scientific and varied from 6.5?×?10² to 6.5?×?10³ Kilo Daltons(kDa) by Debye plot. Critical Micelle Concentrations (CMC) of the synthesized polymers was determined using electrical conductivity meter and it ranged from 105 to 125 milligrams per litre (mg L^?1).     

EDTA络合滴定法直接测定记忆合金中镍和钛

镍钛记忆合金是目前广泛用于医学上的一种功能材料,其中镍的质量分数为56％左右,钛的质量分数为44％左右。科研实践证明材料中的镍和钛的含量直接影响其应用性能。因此,快速、准确测定镍和钛的含量在生产过程中极为重要。传统的分析方法有镍一丁二肟重量法、丁二肟沉淀分离-EDTA络合滴定法,但这些方法操作都比较繁琐耗时,不能满足日常快速分析的需要。     

Preparation,Characterization and Electrochemical Behavior of Pd‐Au Alloy Incorporated into Zeolites/Graphite Electrodes

The present article reports the preparation of Pd‐Au alloy incorporated into NaY zeolites layer via simple immersion technique. Pd‐Au particles were incorporated into zeolites cages via Co‐impregnation or alternate impregnation of metal ions. Cyclic voltammetry was used to evaluate the state of the modified electrodes in alkaline media. Surface morphology as well as elemental composition of the modified layer were examined using Scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX).     

聚丙烯釜内合金的结晶行为

结晶度、晶粒尺寸和分布、球晶形貌是聚丙烯材料力学性能的重要影响因素之一.与均聚聚丙烯相比,聚丙烯釜内合金的球晶尺寸较小,球晶形态不完善,有利于其抗冲击强度的提高.为了使聚丙烯釜内合金具有较好的力学性能,需要有尺寸适中的球晶结构以及均匀的球晶分布.同时聚丙烯釜内合金中共聚物组分结晶度的提高有利于材料冲击性能的改善.     

硼酸镍纳米棒溶胶-凝胶法合成及表征

以硝酸镍、硼酸和柠檬酸为原料,采用溶胶凝胶法于150 ℃形成咖啡色干凝胶,再于750 ℃焙烧得到硼酸镍纳米棒。采用XRD、SEM、TEM和FTIR对产物结构和形貌进行表征。结果表明产物为分布均匀的Ni₃(BO₃)₂纳米棒,纳米棒的长度受硝酸镍和硼酸的物质的量之比影响,硼酸用量越大,长度越大。当n_Ni3(BO3)2∶n_N3BO3=1∶3时,纳米棒直径为200~300 nm,长度为2~3 μm。对硼酸镍纳米棒的生长机理进行了探讨, 结果表明, 柠檬酸与镍离子反应产生网状结构的配合物,促使镍源均匀地分散在网格间,为硼酸镍纳米棒的生成提供有利的反应空间。     

担载Ni2（C5H5）2（CO）2催化剂的EXAFS表征

以Ni_2Cp_2(CO)_2(Cp=C_5H_5)为催化剂母体化合物,γ-Al_2O_3,SiO_2为担体制备了担载型镍催化剂,对母体化合物及热分解处理前后的催化剂样品在同步辐射装置上进行了外延X-光精细结构(Extended X-ray Absorpdon Fine Structure)测定,以先进的球面波理论对实验结果进行拟合,标样拟合结果与文献XRD完全一致。催化剂的EXAFS表征结果表明,母体化合物与氧化物担体表面发生了较强的化学作用,镍组分具有较高的分散度,镍在氧化硅表面存在Ni[(O)_8]_n,Ni—Ni两种配位,而在氧化铝表面几乎只存在Ni[(O)s)_n配位,催化剂上Ni—Ni键长比母体化合物Ni—Ni键长增加0.01nm左右,Ni—Ni键的伸长及其配位状态可能对其催化行为有重要影响。     

聚合漆酚-镍配合物的电化学合成与性质研究

探讨了漆酚 (EPU)的电化学聚合及其聚合漆酚 镍配合物 (EPU_Ni2 +)的制备 .采用X光电子能谱、红外光谱、动态机械热分析 (DMTA)、TG_DTA、原子发射光谱 (AES)等手段对配合物(EPU_Ni2 +进行表征 .AES结果表明 :镍含量达 7.5 % .由于存在着Ni2 +与EPU的配位作用 ,并引起进一步交联 ,从而提高了玻璃化转变温度和耐热性能     

新型氢氧化镍正极材料的制备和表征

选取Co、Zn、Ca、Mg、Cu等元素与Ni元素按照一定的化学计量比"合金化",实行修饰或掺杂,制备出新型氢氧化镍(New Type Nickel Hyclroxide,NTNH).利用X射线衍射、扫描电镜和恒电流充放电技术测试其相结构、表面微观形貌和充放电性能.研究结果表明:和商业产品相比,新型氢氧化镍具有良好的高温大电流充放电性能和循环稳定性.实现多种元素共沉积,利用元素之间的协同效应,是改善氢氧化镍正极材料高温大电流充放电性能的一条有效途径.     

镍在乳状液膜体系中的迁移行为

研究了镍在乳状液膜分离体系中的迁移行为。在此分离体系中,以煤油作为膜溶剂,span80为表面活性剂,磷酸三丁酯(TBP)为载体。详细讨论了制乳时间和混合时间、span80和TBP浓度、乳水比和油内比、内相NH。和外相HCl的浓度对镍迁移率的影响,确立了最佳分离条件。     

非晶合金NiB催化芳环及硝基的加氢性能

催化氢化;非晶合金NiB催化芳环及硝基的加氢性能     

磁场下化学镀Co-Ni-B-Ce合金层微观形貌和耐磨性

磁场下化学镀Co-Ni-B-Ce合金层微观形貌和耐磨性;化学镀钴-镍-硼合金;铈;表面形貌;磁场