由氯化钴制备四羰基钴盐的反应动力学

由氯化钴与ＣＯ制备四羰基钴盐是一个多相羰化反应，本文研究了影响反应速度的主要因素，测定了３２３～３４３Ｋ温度范围的动力学数据，根据实验数据得出反应速度方程式为：－ｄ（ＣｏＣｌ２）／ｄｔ＝ｋ（ＣｏＣｌ２）（Ｒｅｄ）反应活化能为７４．０３ｋＪ．ｍｏｌ＾－１。     

Cobalt Aluminate Formation in Alumina-Supported Cobalt Catalysts: Effects of Cobalt Reduction State and Water Vapor

The gas phase hydrodechlorination (HDC) of chlorobenzene (at 523 K) was studied over Ni/SiO₂ (prepared by precipitation-deposition and impregnation) and Ni-impregnated Al₂O₃, MgO, activated carbon and graphite; the Ni loading spanned the range 1.5-20.3% w/w. The activated catalysts (with and without precalcination) were characterized by TEM/H₂ chemisorption and the Ni particle size (distribution) is related to HDC activity. The levels of reversibly and irreversibly held Cl on the used catalysts were recorded: spent Ni/MgO bore the highest residual Cl. The reaction is structure sensitive, with an increase in specific HDC rate at higher (average) Ni particle sizes over the range 1.4–22.1 nm. The exception to this trend is Ni/graphite and (to a lesser extent) Ni/Al₂O₃, where Ni-support interactions are responsible for the lowering HDC activity.     

福美钠钴渣回收钴的实验研究

采用"低酸酸洗-两段焙烧-溶剂萃取"工艺对福美钠钴渣回收工艺进行了研究,考察了氧化焙烧温度、焙烧时间、硫酸化焙烧温度、硫酸加入量等因素对钴浸出率的影响。结果表明:氧化焙烧最佳温度500℃,焙烧时间为0. 5～1 h,硫酸化焙烧温度400℃,硫酸加入量为干焙砂60%～70%(质量比),焙烧时间0. 5 h,钴浸出率可达99%。     

快速测定镍钴合金镀液中的镍和钴

采用分光光度法快速直接测定共存在镀液中常量和镍和钴。在７２０ｎｍ波长处测定镍时,钴不干扰。在５１０ｎｍ波长处测定钴时,镍对钴的吸光度的干扰值与镍量呈线性关系,因而采用扣除相应镍量所造成吸光度增加的方法消除镍对钴的干扰。     

Effect of Cobalt Precursors on the Dispersion of Cobalt on MCM-41

The photocatalytic activity of titanium dioxide supported on zeolites HZSM-5, HY and H was evaluated for a novel intermolecular cyclization of ethylenediamine with propylene glycol leading to dihydropyrazine. Titanium dioxide supported on zeolites has been prepared with 2 and 5 wt% of TiO₂ by solid-state reaction, impregnation and sol impregnation methods. From the characterization by XRD, BET, EDAX and TPD of NH₃, it is deduced that in all cases titanium dioxide is in small particles of anatase on zeolites. The highest photocatalytic activity was obtained with 2 wt% TiO₂/H prepared by solid-state reaction. The acidity determined by TPD of NH₃ was found to be lower for TiO₂/H than for TiO₂/HZSM-5 and TiO₂/HY. From the above observations, it can be concluded that adsorption, acidity and structure of zeolites have an influence on the activity of supported TiO₂.     

Bimetallic Cobalt Based Catalysts

Highly dispersed, oxide- or zeolite-supported bimetallic catalysts are widely used in the catalytic industry, such as in catalytic reforming, nitrogen industry and gas-to-liquid technology. The paper highlights the nano-sized Co-based bimetallic system in terms of correlation between structure and reactivity/selectivity promoted by the second metal. Opposite to the bulk alloys nano-sized bimetallic catalysts are extremely sensitive to the structure, morphology, valence state of the supporting oxide material in which the nano-particles are embedded. In this case, one of the less reducible components, which strongly interact with the supports, may stabilize the second, more noble metals, and thus the latter can be stabilized in highly dispersed state. Conversely, addition of noble metal to the hardly reducible component may facilitate reduction, which causes the retardation of the deactivation process of some hydrocarbon reaction. The future trend is the application of bimetallic nano-particles although careful consideration and experimentation should be taken to elucidate the structure of such type of catalyst. The various effects of Co-based bimetallic particles, such as particle size, metal/support interface, morphology and electronic effects, on the activity/selectivity in given catalytic reactions will be discussed.     

Polymorphs of Cobalt Oxide

Through controlled thermal decomposition of cobalt acetate tetrahydrate, cobalt monoxide can be synthesized with three different crystal structures: rock salt, zinc blende, and wurtzite. Using electron microscopy techniques, it is shown that the polymorphs exhibit characteristic crystallite morphologies; "tetrahedral" for the zinc blende type and "lathlike" for the wurtzite form. Atomistic simulation calculations predict the lattice energies of the three polymorphs to be relatively close, with the rock salt polymorph being most stable, followed by the wurtzite form and lastly zinc blende.     

环烷酸钴的制备

论述了以金属钴和环烷酸为原料合成环烷酸钴的工艺，考察了氯化钴合成工艺和处理工艺，氯化钴浓度，环烷酸酸值，碱浓度对环烷酸钴钴含量的影响，合成的氯化钴经处理达到国家标准要求，合成的氯化钴不经处理可直接用于合成环烷酸钴，产品环烷酸钴达到技术指标要求。     

单盐滚镀黑钴工艺

1前言 普利民厂是德国在华独资生产金属钮扣企业,产品出口欧美为主.因镍对某些人的皮肤过敏,因而含有镍的镀层的金属钮扣无法出口.3年前,我厂研究开发了深枪黑锡钴合金代替深枪黑锡镍合金,并成为我厂主导颜色的镀种.但因市场竞争剧烈,该工艺配方成分多,成本高,且为电镀合金,镀液维护较困难.因而需要环保型、低成本、高质量的单金属黑色镀层来取代无镍枪黑锡钴合金,于是半年前我厂开始研究开发电镀黑钴工艺,并已取得成功.现把该工艺介绍如下.     

新癸酸钴中不同氧化态钴的分离及测定

研究新癸酸钴中不同氧化态钴分离及测定的方法。根据二价钴和三价钴与乙酰丙酮形成的配合物溶解性的不同,实现不同氧化态钴的有效分离;根据配合物稳定常数的不同,利用络合滴定法,测定新癸酸钴中二价钴含量。用本方法对自制及市售新癸酸钴样品的进行分离及测定取得满意的效果。     

从钴废料中回收高纯钴粉的新工艺研究

主要研究了从钴废料中回收高纯钴粉的实验条件。通过实验得出,在一定碱性条件下提取钴废料中的钴,以水合联氨为还原剂,在85℃下液相还原得到纯度为97％的钴粉,回收率达91．3％。     

Oxidation of Sintered Cobalt Oxide

The kinetics and mechanism of the oxidation of sintered pellets of CoO and Co_0.5Mg_0.5O in air at high temperatures were investigated to find stable heat sources containing ⁶⁰Co. The initial stages of oxidation of both materials were nuclei-growth-controlled, i.e. In [1/(1-X)] =kt^m. The reaction rate constant for CoO decreased at 800° to 960°C, the temperature where the cobalt oxide spinel decomposed. The reaction-rate constant for decomposition of the mixed oxide was maximum at 700°C and decreased at higher temperatures. This decrease confirmed the validity of the nuclei-growth solid-state reaction-rate equations.     

Cobalt impurities in synthetic diamond

High-quality single crystals of diamond were grown by the temperature-gradient method using cobalt-containing metals as the solvent-catalyst. Cobalt and nickel impurities in the crystals were measured by X-ray fluorescence using synchrotron radiation. Their distributions were imaged by a mapping technique. Their concentrations were also measured at a number of points of the crystals. X-ray absorption near edge structure (XANES) spectroscopic measurements were carried out to investigate the bonding nature of the impurities. It was confirmed that the cobalt impurity distributes preferentially in the {111} sectors like nickel. We found that the concentration of cobalt is in proportional correlation with that of nickel in crystals grown from alloys containing both cobalt and nickel, and that cobalt is more difficult to incorporate than nickel. The XANES measurements revealed that the cobalt impurity occupies tetrahedral sites like nickel.     

环戊二烯基钴配合物的研究进展

综述了环戊二烯基钴化学的研究进展,着重介绍了其配合物的类型、合成方法、反应性及其在炔烃和腈环加成反应中的催化作用.     

粘合剂中钴的测定

以孔雀绿为衬托剂，二甲酚橙为指示剂，在ｐＨ５～６的六次甲基四胺缓冲体系中用ＥＤＴＡ直接滴定测钴。方法快速、简便，应用于粘合剂中钴的测定，结果满意     

钴氧化物的电化学制备及超级电容性能研究

本文采用便捷绿色的电化学交流电法以金属钴为前驱体合成了Co(OH)_(0.225)(SO_4)_(0.925)/Co_3O_4复合物。扫描电子显微镜及透射电子显微镜表征说明其形貌为纳米颗粒,XRD表征说明其物相为正交Co(OH)_(0.225)(SO_4)_(0.925)和立方Co_3O_4的混合物。该材料应用于超级电容器具有较好的电化学性能。     

微波加热CoCl2·6H2O的脱水研究

研究了水合氯化钴微波脱水新工艺,与常规热风干燥工艺相比较,微波干燥8min的脱水效果与100℃热风干燥60min的效果相当.     

国产新癸酸钴的应用性能研究

研究对比国内外不同厂家生产的4种新癸酸钴产品使用性能的差异。试验结果表明,国产新癸酸钴A胶料的物理性能和分散性优于进口新癸酸钴胶料,粘合性能与进口新癸酸钴B胶料相当,优于进口新癸酸钴C胶料。国产新癸酸钴完全可以替代进口新癸酸钴用于钢丝帘布胶。     

Fischer-Tropsch Synthesis over Modified Cobalt Catalysts

The catalysts of Co/Zr-SiO2 were prepared by precipitation and the promoter of Pt was supported by impregnation. The reducibility of the cobalt oxide and the other physicochemical properties of the catalysts were characterized by TPR, TPD, BET and XPS. With the evaluation of the reduction temperature, the reduction degree increased but the surface area of the catalysts and the adsorption property for reactant CO distinctly decreased; The addition of Pt resulted in the improvement of the reducibility by decreasing the reduction temperature of cobalt oxide species. The FT-synthesis has been performed in a quartz fixed-bed reactor, and the experimental results showed that the best activity for promoted catalyst has been found at the reduction temperature of 400℃, in spite of its uncompleted reduction.