燃烧催化剂对EMCDB推进剂交联固化反应的催化作用

设计了一种研究燃烧催化剂对EMCDB推进剂交联固化反应催化作用的实验方法，比较了十多种铅盐、铜盐对交联固化反应催化活性的强弱，筛选出了可用作粒铸EMCDB推进剂燃烧催化剂的铅盐、铜盐。实验结果表明，某些铅盐对交联固化反应有较强的催化加速作用，铜盐和炭黑对交 联固化反应没有明显的催化加速作用，只有对交联固化反应催化加速作用很小的铅盐才能用作EMCDB推进的燃料催化剂。     

含硫化合物在羰基钴盐合成中的应用

研究了利用低价含硫化合物的强配位能力和还原性及它作为助剂催化引发氯化钴的羰化反应的工艺条件，以便在较低的ＣＯ压力下合成四羰基钴盐。对几种常见含硫化合物的引发反应效果进行了对比。结果表明少量的含硫化合物可以引发钴盐的羰化反应，过多的添加则会阻断氯苄羰化反应的催化作用。     

对氨基苯甲酸钴盐及镍盐对天然橡胶与黄铜粘合的增进作用

本文研究了对氨基苯甲酸钴和对氨基苯甲酸镍(以下简称钴盐、镍盐)对天然橡胶与黄铜粘合的影响。结果表明,在胶科中添加一定量的钴盐和镍盐都能提高橡胶与黄铜的粘合强度,其中以添加一定量钴盐的胶料更为突出,且钴盐在较宽的变量范围内对胶料     

钴盐催化甲苯液相选择氧化反应研究进展

介绍了现阶段钴盐催化甲苯液相选择氧化所使用的各种工艺、钴盐和钴盐复合催化剂在有无溶剂或助剂作用下的催化情况。探讨了现阶段钴盐催化氧化甲苯所存在的催化剂活性,甲苯转化率、产品选择性以及纯度等问题,指出了未来钴盐催化氧化甲苯的发展方向应该是寻求一种高效绿色并且可以提高甲苯转化率、产物选择性的钴盐催化剂。     

钴盐催化甲苯液相选择氧化反应研究进展

介绍了现阶段钴盐催化甲苯液相选择氧化所使用的各种工艺、钴盐和钴盐复合催化剂在有无溶剂或助剂作用下的催化情况。探讨了现阶段钴盐催化氧化甲苯所存在的催化剂活性,甲苯转化率、产品选择性以及纯度等问题,指出了未来钴盐催化氧化甲苯的发展方向应该是寻求一种高效绿色并且可以提高甲苯转化率、产物选择性的钴盐催化剂。     

不饱和聚酯树脂BPO/DMA固化体系的研究

采用过氧化苯甲酰/N,N-二甲基苯胺(DMA)固化体系室温条件下对不饱和聚酯树脂(UPR)进行固化,可以降低常用的过氧化酮/钴盐体系的危险性。研究了BPO用量为2%时常压条件下改变促进剂N,N-二甲基苯胺用量对不饱和聚酯树脂凝胶和固化特性及后处理对固化物性能的影响,得出不饱和聚酯树脂∶过氧化苯甲酰∶N,N-二甲基苯胺最佳比为100∶2.0∶0.2,力学性能最好、吸水性低;后处理会较大程度的改善固化物的力学性能和吸水性,弯曲强度提高约50%,吸水率降低约50%。     

钴-钾-d-钙促进剂协同效应的研究

<正> 目前,国内外不饱和聚酯树脂(以下简称UP)最常用的室温固化引发剂是过氧化环己酮和过氧化甲乙酮。而与其配合的促进剂是金属有机化合物如:钴、锰、钒等金属盐。几十年来,人们一直认为:钴盐促进剂固化性能好,在UP室温固化中广泛采用,但由于受气温和钴盐色泽的影响,近年来人们     

碳纳米管/环氧树脂体系固化工艺研究

研究了碳纳米管/环氧树脂体系固化过程的工艺条件。结果表明,实验过程中操作温度120℃,固化过程中起始固化温度120℃,固化温度180℃,碳纳米管/环氧树脂复合体系的固化动力学模型为自催化模型。添加碳纳米管会使复合材料的拉伸强度变强,但是当碳纳米管的质量分数达到1.5%时拉伸性能反而会下降。     

环己烷氧化分解工艺技术的进一步研究和开发

对环己烷液相氧化法生产环己酮的工艺技术进行了理论和试验研究。根据谢苗洛夫的自由基理论等,结合生产装置的实际数据,研究了环己烷钴盐催化氧化和无催化氧化工艺,并进行理论推导,得出了环己烷氧化的数学模型,开发了催化氧化和无催化氧化相结合的新工艺;对环己基过氧化氢均相和非均相催化分解工艺在理论研究的基础上,通过实验室试验验证,开发了拟均相催化分解的新工艺。     

双水杨醛缩乙二胺合钴配合物的合成及应用研究

以Shiff碱为配体的钴配合物,具有更强的生物活性与催化效率。单因素实验、正交实验探究不同条件对Schiff碱配体合成及其催化性能的影响,结果表明:钴配合物合成的较优的实验条件为双水杨醛缩乙二胺用量4 g(0.015 mol)、用醋酸钴为钴盐、钴离子的量为0.015 mol、反应温度60℃、反应时间60 min,收率在63.5%以上;以Co(Salen)作为催化剂时,氧化安息香,较优催化条件为催化剂0.4 g、反应温度65℃、反应时间60 min、KOH 0.2 g,产率可达72.5%。     

Catalytic oxidation of sulphide ions to elementary sulphur in aqueous solutions over transition metal oxides

The catalytic activity of a wide range of transition metal oxides in oxidation of sulphide ions by air in aqueous medium was studied. Some specific features of the reaction mechanism on some of the studied oxides were considered. The transition metal oxides are promising catalysts for practical application. Some of these oxides will allow the preparation of catalysts possessing activity comparable to that of the cobalt phthalocyanine based catalysts, popular in industrial practice.     

Synthesis of polymer-supported metal-ion complexes and evaluation of their catalytic activities

Polymer-supported transition-metal-ion complexes of the N,N′-bis(o-hydroxy acetophenone) propylenediamine (HPPn) Schiff base were prepared by the complexation of iron(III), cobalt(II), and nickel(II) ions on a polymer-anchored N,N′-bis(5-amino-o-hydroxy acetophenone) propylenediamine Schiff base. The complexation of iron(III), cobalt(II), and nickel(II) ions on the polymer-anchored HPPn Schiff base was 83.44, 82.92, and 89.58 wt%, respectively, whereas the unsupported HPPn Schiff base showed 82.29, 81.18, and 87.29 wt % complexation of these metal ions. The iron(III) ion complexes of the HPPn Schiff base showed octahedral geometry, whereas the cobalt(II) and nickel(II) ion complexes were square planar in shape, as suggested by spectral and magnetic measurements. The thermal stability of the HPPn Schiff base increased with the complexation of metal ions, as evidenced by thermogravimetric analysis. The HPPn Schiff base showed a weight loss of 51.0 wt % at 500°C, but its iron(III), cobalt(II), and nickel(II) ion complexes showed weight losses of 27.0, 35.0, and 44.7 wt % at the same temperature. The catalytic activity of the unsupported and supported metal-ion complexes was analyzed by the study of the oxidation of phenol and epoxidation of cyclohexene in the presence of hydrogen peroxide. The supported HPPn Schiff base complexes of iron(III) ions showed a 73.0 wt % maximum conversion of phenol and 90.6 wt % epoxidation of cyclohexene, but unsupported complexes of iron(III) ions showed 63.8 wt % conversion of phenol and 83.2 wt % epoxidation of cyclohexene. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 93.1 wt % and 98.1 wt % with the supported HPPn Schiff base complexes of iron(III) ions, but it was low with the supported Schiff base complexes of cobalt(II) and nickel(II) ions. The selectivity for CTL and ECH varied with the molar ratio of the metal ions but remained unaffected by the molar ratio of hydrogen peroxide to the substrate. The energy of activation for the epoxidation of cyclohexene and oxidation of phenol with the polymer-supported Schiff base complexes of iron(III) ions was 10.0 and 12.7 kJ/mol, respectively, but it was found to be higher with the supported HPPn Schiff base complexes of cobalt(II) and nickel(II) ions and with the unsupported HPPn Schiff base complexes of iron(III), cobalt(II), and nickel(II) ions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Treatment of wastewater containing copper,zinc, nickel and cobalt using Duolite ES‐467

Duolite ES‐467 was used to treat wastewater containing heavy metal ions. Sorption experiments were carried out at varying pH values, agitation speeds, reaction times, and metal ion and sorbent concentrations. Each of the parameters affects the sorption behaviour of individual metal ions. Copper sorption was greater compared with other metal ions such as zinc, nickel and cobalt. The presence of other metal ions affects copper sorption. Equilibrium isotherm curves were developed. These were used to predict that the metal ion concentration would be reduced from 100 to less than 1 mg dm^?3. Fixed bed tests were conducted to investigate the efficiency of Duolite ES‐467 for the selective removal of copper ions from multi‐metal solutions. Breakthrough curves were obtained using Duolite ES‐467 for solutions containing copper, nickel and copper, zinc, nickel and cobalt. Elution studies were also carried out using sulfuric acid. © 2002 Society of Chemical Industry     

硅氢加成反应催化机理的研究进展

综述了硅氢加成反应的三大催化机理(自由基加成机理)、离子加成机理、配位加成机理的研究动向及发展,着重介绍了配位加成机理中的铂催化机理(Chalk-Harrod机理、硅基迁移、铂胶体过渡态机理、钴催化机理、铑催化机理、钌催化机理、钯催化机理、镍催化机理等.)     

金属离子对产油微生物油脂积累影响的研究进展

利用产油微生物合成含量丰富的油脂,对于解决石化能源日益紧缺问题,改善人类生活水平具有重要意义.金属离子能影响产油微生物生长形态、细胞内外渗透压和油脂合成关键酶活力等,对产油微生物油脂合成有重要的调控作用.本文首先介绍了产油微生物的产油机制,随后重点阐述了金属离子对产油微生物油脂积累的影响及其分子机理,最后对进一步探讨金属离子在产油微生物发酵过程中的作用研究提出一些建议.文章指出由于产油微生物油脂合成途径不尽相同,在工业上利用产油微生物生产油脂时,应从该微生物油脂合成的主要途径入手,找出该途径中的关键酶,随后充分考虑不同微生物对金属离子的耐受性、不同金属离子对微生物形态和胞内关键酶活力的影响,以及不同金属离子之间对同种关键酶的活性中心是否存在竞争或协同的关系等,从而制定可行的金属离子添加控制策略.     

Effect of the nature of the crosslinking agent on the metal‐ion complexation characteristics of 4 mol % DVB‐ and NNMBA‐crosslinked polyacrylamide‐supported glycines

Metal‐ion complexation behavior of glycine functions supported on divinylbenzene (DVB)‐ and N,N′‐methylene bisacrylamide (NNMBA)‐crosslinked polyacrylamide was carried out toward Co(II), Ni(II), Cu(II), and Zn(II) ions. The polymeric ligands and the derived metal complexes were characterized by IR, UV, and EPR spectra and by SEM. The metal‐ion complexation of the rigid DVB‐crosslinked system is lower than that of the semirigid NNMBA‐crosslinked system. The glycine ligands renervated after the desorption of the metal ions showed an unusual specificity toward the desorbed metal ion. The low degree of crosslinking makes the desorption process simple and shows fast rebinding kinetics. The metal‐ion‐desorbed polymeric ligands would have pockets or holes characteristic of the desorbed metal ion, resulting in its specific rebinding. The rigidity of the crosslinking also determines the kinetics of metal‐ion rebinding. The specificity and selectivity characteristics of the crosslinked polymeric ligand was found to be increased as the crosslinking agent changes from semirigid NNMBA to rigid and hydrophobic DVB. Thus, copper‐desorbed resins showed an increased specificity toward copper ions and selectively binds copper ions from a mixture of copper and cobalt ions. The metal‐ion specificity and selectivity characteristics of the metal‐ion‐desorbed system is exploited for the concentration of desorbed metal ions from a mixture of metal ions. The resin is amenable for a continuous process and can be regenerated several times. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3432–3444, 1999     

Study on the catalytic behavior of metal acetylacetonates for epoxy curing reactions

Metal acetylacetonates are effective latent catalysts for epoxy/anhydride systems. A screen test on the catalytic behavior of metal acetylacetonate shows that this system offers a wide range of curing latency and material properties. It can be inferred that the curing behavior is closely related to the bonding strength of the metal ion to the ligand. Isothermal kinetic study on the catalytic behavior of metal chelates with first‐row transition metal ions is conducted and analyzed by using an autocatalytic model. It is found that the activation energy of the system containing the divalent metal chelates follows the Irving and Williams rule. The activation energies of the reaction obtained in the kinetic study are compared with the dissociation energies of the metal/ligand bond and the results are discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1572–1579, 2002     

Augmenting the photocatalytic performance of cobalt ferrite via change in structural and optical properties with the introduction of different rare earth metal ions

In the present study, synthesis of different rare earth (RE) doped cobalt ferrite nanoparticles was done via facile sol-gel auto-combustion method using four different RE metal ions: Eu, Gd, Dy and Nd. The RE substituted cobalt ferrite nanoparticles were then characterized using FT-IR, powder XRD, HR-TEM, SAED, EDX, VSM and DRS techniques. From the characterization results, a significant variation in the structural, magnetic and optical properties of pure cobalt ferrite was observed with the introduction of different RE metal ions. This change in the properties was emerged due to the distortion of the ferrite crystal lattice due to replacement of smaller ionic radii Fe³⁺ ions with the comparatively larger ionic radii RE³⁺ metal ions. The catalytic activity of the fabricated RE doped cobalt ferrite nanoparticles was studied for the photo-Fenton degradation of cationic and anionic dyes. Under visible light irradiation, the as prepared RE doped nanoparticles exhibited great enhancement in the photo-Fenton degradation of dye molecules as compared to pure cobalt ferrite nanoparticles. The enhancement in the degradation rate was ascribed to the generation of defects in the crystal lattice, lower crystallite size and reduced band gap energy values which facilitated the facile transfer of photo-generated holes and electrons. Best catalytic results were obtained for CoNd_0.08Fe_1.92O₄ for SO dye (k?=?2.23?×?10^?1 min^?1) which were found to be around 9 times higher than the pure cobalt ferrite nanoparticles (k?=?0.23?×?10^?1 min^?1).     

Higher Oxidation State Responsible for Ozone Decomposition at Room Temperature over Manganese and Cobalt Oxides: Effect of Calcination Temperature

The heterogeneous catalytic decomposition of ozone was investigated over unsupported manganese and cobalt oxide at room temperature. All catalysts were characterized by X-ray diffraction (XRD), N₂ adsorption–desorption (Brunauer–Emmet–Teller method), H₂-temperature programmed reduction (H₂-TPR) and X-ray photoelectron spectroscopy (XPS). The catalytic activity test indicated that these oxides had a good activity on ozone conversion meanwhile the catalysts remained highly active over time under reaction conditions. The treated temperature of the catalyst had a significant impact on the performance of ozone abatement and the samples treated at lower temperature showed higher activity. The surface area decreased obviously when developing the calcination temperature and H₂-TPR results demonstrated that much higher oxidation state of metal ions and active oxygen species were maintained on the surface under low treated temperature. XPS analysis showed that there were higher oxidation states of metal ions (Mn⁴⁺ and Co³⁺) and adsorbed oxygen species on the surface of catalysts treated at lower temperature, both of which play a significant role in ozone decomposition. However, the activity of manganese oxide was higher than that of cobalt oxide and the possible reason for this phenomenon was discussed.     

Electrochemical Reduction of Oxygen at Pyrolyzed Iron and Cobalt N4‐Chelates on Carbon Black Supports

Besides platinum, various nonnoble metal compounds, when prepared appropriately, are suitable for the electrochemical reduction of oxygen in liquid electrolytes and PEM‐fuel cells. Pyrolyzed N4‐chelates, such as phthalocyanines, tetraazaannulenes and porphyrins with a central metal atom of iron or cobalt, are a very important group of compounds and have been investigated in the past. It was found that the catalytic activity, especially of phthalocyanines, was high when prepared on carbon black supports at high temperatures (400–900 °C). Investigations on tetraazaannulenes and porphyrins yielded similar results. Non‐noble metal compounds of cyclame (1,4,8,11‐tetraazacyclotetradecane), which are also N4‐chelates, were not investigated as thoroughly. However, the catalytic activities of iron and cobalt cyclames were low, compared to those of phthalocyanines. With the (GC‐MS) analysis of both decomposition products, it could be shown that the mechanism of the N4‐chelate decomposition is of decisive importance for the catalytic activity.