NiFe2O4-M金属陶瓷惰性阳极成分设计的热力学分析

NiFe2O4-M金属陶瓷惰性阳极由氧化物陶瓷相和金属相组成.多数美国专利认为Fe,Ni,Cu,Co,Ti,Cr,Mn,Al,Pd,Ag,V,Zr,Y,La,Ta,Nb,Sc,Hf,Ca,Sn,Zn等21种金属均适合作为上述阳极的金属相成分.但文中的热力学详细分析计算结果表明:在上述前8种金属中,仅有Cu,Ni 2种适...     

金属添加剂对Ni-B非晶态合金催化剂邻氯硝基苯加氢性能的影响

研究金属添加剂（Cr、Mn、Fe、Co、Cu、Mo和Zn）负载的Ni-B非晶态合金催化剂催化加氢制备邻氯苯胺的影响。结果表明,适量的Zn、Cr和Mo能提高催化剂的活性和选择性,Mn对催化剂的活性和选择性影响不大,Fe、Co和Cu降低催化剂的活性。这与能和硝基形成多位吸附的单元镍以及电子因素有关。     

Electrolyte solutions in liquid ammonia—IX. Electrodeposition and electrodissolution of metals from their salts

Anodic dissolution and cathodic deposition of 20 transition metals in acidic solutions in liquid ammonia has been surveyed. The early transition metal elements Ti, Zr, V Nb, Mo and W form high oxidation-state insoluble amido complexes during anodic oxidation. Soluble ammines of normal metal oxidation states are produced with Cr(III), Mn(II), Fe(II), Co(III), Ni(II), Cu(II), Ag(I), Zn(II), Cd(II) and Hg(II) (Mn dissolves spontaneously). The metals Ru, Pd, Pt and Au only dissolve slightly after prolonged electrolysis. Anodic enrichment of Au in its alloys is unlike that in aqueous solution; in ammonia both Cu and Ag can be simultaneously depleted from a 9 carat gold alloy. Cathodic reduction of metal-bearing solutions follows wide variations of behaviour. Fe and Ru ammines reduce to amido-complexes with concomittant hydrogen evolution, but Cr is not reduced. Solutions of Mn, Co, Ni, Pd, Pt, Ag, Au, Zn, Cd and Hg give metallic cathode deposits under differing conditions. Electrodeposition is potential dependent for Ni, Cu and Ag; metal plate at low potentials, and powders at high potentials. The two different products are the result of reduction of species with different degrees of solvation.     

Geochemical implications of trace elements and sulfur in the saturate, aromatic and resin fractions of crude oil from the Mara and Mara Oeste fields, Venezuela

Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the saturate, aromatic and resin fractions of 15 crude oils from Mara (DM) and Mara Oeste (DMO) fields of the Maracaibo Basin, Venezuela. The oils studied are classified as unaltered or altered by biodegradation. In the altered oil, the depletion of n-alkanes, the absence of isoprenoids and the presence of steranes and hopanes unaltered by biodegradation are indicative of moderate biodegradation. The elements Zn, Fe, Mn, Cu, Ni, and Sr were detected in the saturated hydrocarbon fraction; Cr and V were detected in the aromatic fraction in addition to the above elements; whereas the elements detected for the resin fraction were Cr, Zn, Fe, Cu, Ni, Mo, V, and Sr. Co was not detected in any fractions of the oils analyzed. Sulfur was found in all fractions of the oils studied. It was proposed that Fe, Zn, Sr, and Mn could have entered the oil during migration or Fe, Zn and Mn as pollutants during oil extraction. Cr and Cu may be of biological origin and Mo could be incorporated into the reservoir through bacteria. Only S, V, and Ni in the resin fractions can be used as indicators of the origin and correlation of Mara and Mara Oeste oils. Based on the results obtained in this work, it can be established that the V/(V+Ni) ratio in the resin fraction can be used as a correlation parameter, for these oils.     

Transition metal doped mesoporous titania with a crystalline framework as catalysts for oxidation of -bromotoluene to -bromobenzaldehyde

Transition metal M (M = Mn, Fe, Co, Ni, Cu, and Zn) doped mesoporous titania with a crystalline framework was employed as catalysts for the oxidation of p-bromotoluene (PBT) to p-bromobenzaldehyde (BBD) in acetic acid using aqueous hydrogen peroxide as oxidant. It was found that mesoporous TiO₂ doped with those metals (Fe, Co and Ni) whose atomic radii are relatively smaller exhibited higher conversion rate of PBT. Among these catalysts, the Co/meso-TiO₂ exhibited high substrate conversion and good product (p-bromobenzaldehyde) selectivity plus it can be reused once with almost the same activity. The effect of different Ti/Co (molar) ratio on the activities of Co/meso-TiO₂ was also investigated.     

Alterung des polybutadies bei anwesenheit von metallverbindungen

In the ageing of industrial polybutadienes the effect of decomposition products of ZIEGLER–NATTA catalysts could not be distinguished from other Important factors. However, the additional introduction of Co, Ti or Ni compounds (components of the ZIEGLER-NATTA catalysts) has influenced the oxidation process. The effect of different acetylacetonates (Ti, Co, Ni, V, Al, Cc, Mn, Cu) on the oxidation of purified polybutadiene in presence or in absence of an antioxidant has further been studied. The apparent activation energies of oxidation have been estimated and possible mechanismus of the actions of metal compounds in the oxidation of polybutadiene have been proposed.     

Oxidation of cycloalkanes with molecular oxygen in the presence of salen metallocomplexes in thermomorphic conditions

The oxidation of cycloalkanes with molecular oxygen, catalyzed by two groups of metallosalen complexes, was studied. The first group consisted of salen complexes with different metals such as Mn, Fe, Co, Ni, Cu, Zn, while the second group was composed of manganese salen complexes with different substituents (t-butyl electron-donating substituents and/or electron-withdrawing perfluoroalkyl substituents). Mn, Fe and Co salen complexes are the most active catalysts, while Ni, Cu and Zn salen complexes are far less efficient. The introduction of t-butyl electron-donating substituents into Mnsalen complex increases the catalytic activity and catalysts solubility in the reaction mixture. The introduction of perfluoroalkyl electron-withdrawing substituents enhances the catalytic activity and renders the solubility of the catalyst temperature dependent (thermomorphic behaviour), thus allowing one to recover them easily after the reaction by simply cooling the system to room temperature. The synthesis of two new manganese salen complexes with perfluoroalkyl substituents was elaborated.     

Study of the degradation of polyurethanes. I. The effect of various metal acetylacetonates on the photodegradation of polyurethanes

Photodegradation of polyurethanes based on polyester diol-diphenylmethane-p,′p-diisocyanate in the absence and presence of various metal acetylacetonates (Ti, V, Cr, Mn, Co(II), Co(III), Fe, Ni, Cu, Zn, Mg, Al, and Sn) was carried out; and the effect of these metal compounds on the degradation was examined by investigating the changes in the stress–strain properties and infrared- and ultraviolet-visible spectra of the polymer. The results obtained were as follows: Co(III), Co(II), Cu, Ti, and Sn acetylacetonates substantially enhanced the photo-oxidation of the polyurethane; and Al, Ni, and Zn acetylacetonates scarcely affected, or slightly retarded, it. The other metal acetylacetonates accelerated more or less the photo-oxidation of the polymer. Co(III), Co(II), and Cu acetylacetonates extremely degradation. Wavelength of the irradiated light was responsive to photochemical reactions of functional groups in the polymer. C? N and C? O bonds of urethane groups were very accessible to the photo-irradiation both without and with a glass filter, while methylene groups were rather stable to the irradiated light longer than 300 nm, through a glass filter. The effect of the metal compounds on the coloration of the polymer was also consistent with that of mechanical strength and infrared spectral changes.     

Separation of Metals from Sulfated Deep-Sea Ferromanganese Nodules by Adsorbing Colloid Flotation

Abstract

Adsorbing colloid flotation (ACF) is applied to aqueous leach solutions of sulfated deep-sea ferromanganese nodules and their process tailings. Metal cations of Cu, Co, Ni, Mn, Al, and Zn are separated simultaneously by flotation with hydroxide collectors and cationic surfactants from the leach liquors of sulfated ferromanganese nodules. Applications of ACF to the nodule tailings also makes possible the recovery of residual Cu, Co, Ni, Ti, Zn, Al, Fe, Mn, and the separation of Pb and V, the most abundant toxic species in the nodules and tailings.     

Memory effect-enhanced catalytic ozonation of aqueous phenol and oxalic acid over supported Cu catalysts derived from hydrotalcite

Mg/Al supported metal (Fe, Co, Ni and Cu) oxide catalysts were prepared by co-precipitation of hydrotalcite-like clay materials as precursors, calcined, and used for the ozonation reaction of phenol and oxalic acid. The reaction was carried out using the catalyst and aqueous solution of phenol or oxalic acid in an O₃/O₂ mixed gas-flow at 20 °C. In the ozonation of phenol, the combination of ozone and supported metal oxide catalysts was effective for the removal of total organic carbon (TOC). Also in the ozonation of oxalic acid as the main TOC component, Cu/Mg/Al catalysts showed the highest activity, followed by Ni/Mg/Al catalyst, while both Fe/Mg/Al and Co/Mg/Al catalysts were not active. Leaching of Cu and Ni, probably due to the chelation of metals by oxalic acid, was significantly observed at the beginning of the reaction. However the metal leaching disappeared at the end of the reaction possibly due to the entire consumption of oxalic acid during the reaction. The best result of oxalic acid mineralization was observed over Cu/Mg/Al catalyst calcined at 600 °C, on which least leaching of the metal was detected. Moreover, a “memory effect” of hydrotalcite accelerated the mineralization of oxalic acid over the Cu/Mg/Al catalyst; oxalate anions were captured and decomposed in the reconstituted hydrotalcite interlayer space on the surface of the Cu/Mg/Al catalyst, resulting in a remarkable enhancement in the catalytic activity of the ozonation.     

铁、钴、镍、铜和锌催化剂催化氨硼烷水解产氢性能研究

采用浸渍-还原法制备了铁、钴、镍、铜和锌催化剂,考察了其催化氨硼烷水解产氢性能,并优化了钴催化剂的制备条件和反应条件。结果发现,铁催化剂中铁以Fe₂B合金相存在,钴催化剂中钴以金属钴存在,镍催化剂中镍以金属镍和Ni（OH）₂·2H₂O存在,铜催化剂中铜以金属铜和氧化亚铜存在,锌催化剂中锌以Zn₄SO₄（OH）₆·4H₂O存在。铁、钴、镍、铜和锌催化剂催化氨硼烷水解产氢活性由大到小顺序为钴催化剂、镍催化剂、铜催化剂、铁催化剂、锌催化剂。显然,具有金属钴相的钴催化剂、金属镍相的镍催化剂和金属铜相的铜催化剂催化氨硼烷产氢活性高于具有Fe₂B合金相的铁催化剂。锌催化剂在制备条件下不能被还原为金属相,它几乎没有催化氨硼烷产氢活性。氯化钴与还原剂硼氢化钠的物质的量比为1∶1.3、还原温度为303 K时制备的钴催化剂催化BH₃NH₃水解产氢性能最佳。反应动力学计算表明钴催化剂催化BH₃NH₃水解产氢反应对氨硼烷浓度的反应级数为零级,对钴催化剂浓度的反应级数为一级,活化能为58 kJ/mol。     

Trace metal distribution in fractions of solvent-refined coal by ICP-OES and implications regarding metal speciation

Separations of Amax solvent-refined coal according to its acid/base/neutral components and by selective elution from a silica column (SESC) to yield nine fractions have been carried-out. After ashing with H₂O₂-H₂SO₄, twenty metals (Mg, Al, P, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo, Cd, Sr, Zr, W, Hg and Ba) were analysed by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). A majority of elements (Zn, Cd, Hg, Cr, Mo, W, and Fe) were found concentrated in the acid fraction while Co, Ni and Cu preferred the neutral and base fraction. In the step gradient SESC fractions, the greatest concentration of metal was found in fractions that had been characterized as enriched with phenols.     

Enhanced oxygen absorption into bisulphite solutions containing transition metal ion catalysts

The sulphite oxidation reaction was studied by measuring the oxygen absorption flux from a nitrogen mixture across an unbroken interface into 11 of unsparged, agitated sulfite (10–30 mM) and catalyst (0.01–100 mM Fe, Mn, Co, Cu, Cr, Ni) solution at pH 4–6 and 50°C. The catalytic action of Fe was solubility-limited at 0.01 mM at pH 5 resulting in an enhancement factor of 2.4 at all higher concentrations. Since Mn and Co do not begin to show enhancement until about 1 mM, Fe was the strongest of the three below this level. 0.05–1 mM thiosulfate was an effective inhibitor for Mn catalysed systems but degraded into inert products. Thiosulfate had much less effect on Fe catalysed oxidation. EDTA inhibited Fe catalysis at concentrations equal or above that of the Fe. Catalytic synergism was quantified for combinations of Mn with the other metals. Mn-Fe couples caused absorption fluxes of up to five times that which would be expected from separate individual catalytic contributions.     

微波消解-ICP-OES法测定黑芝麻中的18种矿质元素

采用HNO3/H2O2湿法微波消解制样,利用全谱直读电感耦合等离子原子发射光谱法(ICP-OES),全面详细地分析测定了黑芝麻中的矿质元素,共检出Ca、P、S、Mg、K、Al、Si、Fe、Na、Zn、Se、Sr、Cu、Mn、Ba、B、Ti、Cr等18种矿质元素,RSD值在1.21%～10.1%,其中13种元素在5%以内。黑芝麻中所含人体常量元素Ca、P、S、Mg、K、Na等的质量分数分别为1.79%,1.08%,0.59%,0.43%,0.41%和0.009 1%;微量元素Fe、Zn、Se、Cu、Mn、B、Cr、Sr、Si、Al等的含量分别为18.6,4.55,3.87,1.74,1.62,0.91,3.21,78.8,125.8 mg/100 g,未检出Pb、Hg、Cd、As以及Ni、Co、Mo等元素。     

Affinage electrolytique des ferronickels

Electrorefining of ferronickels is possible in a cell without diaphragm with the electrolyte CaCl₂ 5 M at 98°C.Behavior of the following impurities have been studied: Ag(I), Au(III), Bi(III), Cd(II), Co((II), Cu(I), Fe(II), Hg(II), Ni(II), Pb(II), Pd(II), Sb(III) and Sn(II).The electrochemical system Ni(II)/Ni(O)is much more reversible in this electrolyte and the only other electrochemical system which appears at the same potential is Cu(I)/Cu(O).Ferronickels of 23.2;72.2 and 94.4% in nickel have been refined in this medium without purification of the electrolyte. Nickel of a purity between 98.7 and 99.7% is obtained.In order to increase the nickel purity and for continuous operation of the method a purification of the electrolyte is necessary. Two methods are proposed: anion exchange resin and liquid—liquid extraction with tri-n-butyl phosphate (TBP).Partition coefficients and ion-exchanger capacities are given for following impurities: Fe(III), Fe(II), Co(II), Cu(II), Mn(II), Zn(II), Cr(III) and Pb(II).Percent extracted by TBP for following impurities are given: Fe(III), Fe(II), Co(II), Cu(II), Zn(II), Mn(II), Cr(III), Pb(II), Al(III), Bi(III), Sb(III) and Sn(IV).A continuous purification of the electrolyte by ion-exchange has been done in the refining of a ferronickel 94.4% in nickel. Nickel obtained is 99.74%.CaCl₂ 5 M appears to be a good electrolyte for electro-refining of nickel.     

Transition metal doped mesoporous titania with a crystalline framework as catalysts for oxidation of p-bromotoluene to p-bromobenzaldehyde

Transition metal M (M = Mn, Fe, Co, Ni, Cu, and Zn) doped mesoporous titania with a crystalline framework was employed as catalysts for the oxidation of p-bromotoluene (PBT) to p-bromobenzaldehyde (BBD) in acetic acid using aqueous hydrogen peroxide as oxidant. It was found that mesoporous TiO₂ doped with those metals (Fe, Co and Ni) whose atomic radii are relatively smaller exhibited higher conversion rate of PBT. Among these catalysts, the Co/meso-TiO₂ exhibited high substrate conversion and good product (p-bromobenzaldehyde) selectivity plus it can be reused once with almost the same activity. The effect of different Ti/Co (molar) ratio on the activities of Co/meso-TiO₂ was also investigated.     

Catalytic graphitization of carbons by various metals

A study was made of the catalytic graphitization of carbons by 22 kinds of metals. Heat treatments were carried out at 2600°C for 1 hr and 3000°C for 10 min under argon atmosphere. In graphitizing 3,5-dimethylphenol-formaldehyde resin carbon powder with which 20w/o metal powder (Al, Cr, Mn, Fe, Co, Ni, Ca, Ti, V, Mo and W) was mixed, graphitic carbon was catalytically formed. The first six metals, which belong to the carbon dissolution-precipitation mechanism, gave large graphitic crystal flakes at an early stage of the reaction; the other metals resulted in fine crystals through the carbide formation-decomposition mechanism. For the non-graphitizing phenol formaldehyde resin carbon in which 10w/o metal powder was dispersed, Mg, Si, Ca, Cu and Ge catalyzed formation of only graphitic carbon; and Al, Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W formed both graphitic and turbostratic carbons. Except for Al and Cu, the former effect was exerted by non-transition metals and the latter effect by transition metals. Boron alone markedly accelerated homogeneous graphitization of both kinds of carbon; and Zn, Sn, Sb, Pb and Bi had no catalytic effect. On the basis of these results, the relationships between some properties of the metals, their catalytic abilities and the kind of catalytic effects are discussed.     

Distribution and nature of organic/mineral bound elements in Assam coals, India

This study focuses on the determination and concentration of twelve elements (Na, K, Ca, Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn and Cd) occurring in sub-bituminous Assam coals and their geochemical association. Distribution of these elements between organic and mineral matters was studied. Comparison of the results of three coals has shown that three elements (Mg, Ca and Mn) are significantly organic bound, while five elements (Fe, Co, Ni, Cu and Zn) are significantly mineral bound; Cd is 50% bound to either organic or mineral matter. FTIR and XRD studies reveal qualitative information about the bonding pattern and nature of components of the mineral matters. The results obtained in this study have considerable geochemical and technological interests.     

Porous Co/Co–Ni–Pt nanostructures prepared by galvanic replacement towards methanol electro-oxidation

The nanostructured Co/Co–Ni–Pt catalyst were synthesized by electrodeposition process and galvanic replacement reaction. The alloy prepared on a copper electrode (Cu/Co/Co–Ni–Zn) was dipped in platinum containing alkaline solution to produce a porous Cu/Co/Co–Ni–Pt catalyst. The catalyst was characterized by energy dispersive X-ray and scanning electron microscopy techniques and its electrocatalytic properties were evaluated using cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry techniques. The results showed that the Co/Co–Ni–Pt coatings are porous, and composed of discrete Pt nanoparticles with the crystallite size of about 66 nm. It was shown from cyclic voltammograms in alkaline solutions that the oxidation current of methanol on the nanostructured Cu/Co/Co–Ni–Pt electrode was much higher than that on flat platinum. Electrochemical impedance spectra on the Co/Co–Ni–Pt electrode reveal that the charge transfer resistance decreases with the increase of anodic potentials. All results show that the Co/Co–Ni–Pt catalysts can be potential anode catalysts for the direct methanol fuel cell.     

垂直区熔法测定磷中杂质的平衡分布系数

The equilibrium distribution coefficients of 12 impurities (As, Fe, Ca, Co, Al, Cr, Cu, Mg, Mn, Ni, Pb, Zn) in phosphorus were obtained by measuring their effective distribution coefficients at zone travel rate of 3, 5, 10, 15, and 20 mm•h1 in the purification process with vertical zone-melting technique. The results indicate that the method is reliable. The equilibrium distribution coefficients are below 0.3 except arsenic.