金属阳极涂层的析氧电位

以金属阳极涂层的析氯电位检测方法为基础，在进行部分改变后，对金属阳极的析氧电位进行检测。在十几个金属阳极生产（修复）单位，实际生产的金属阳极产品抽取的试样中，以对几十个试片的析氧电位检测结果为依据，进行分析讨论，给出了不同涂层的析氧极化情况，析氧电位和的氧析氯电位差的统计情况。同时证明，甘汞电极也可以做为金属阳极涂层析氧电位检测的参比电极。     

银基析氧催化剂的研究进展

近年来基于阳极析氧催化的电解水制氢技术引起了广泛关注,安全、高效的阳极析氧催化剂是实现该技术的核心。银基析氧催化剂具有操作条件温和、析氧过电位低及结构易于调变的特性,是一种颇具发展前景的新型阳极析氧催化剂。本文综述了Ag基析氧催化剂的制备及其在电解水制氢方面的应用,着重介绍了Ag基析氧催化剂的两种调控改性方法,包括原位调控方法和后制备调控方法,其中原位调控方法主要有电解质溶液的匹配、电解质(浓度、酸碱度、温度)的调变和工作电极的修饰,后制备调控方法主要有金属氧化物复合、石墨烯复合和银氧化物纳米晶的调控。将原位调控和后制备调控相结合,可为制备具有较低过电势、较高催化活性的新型Ag基阳极析氧催化剂提供方法指导和为后续研究提供依据。     

低氯超电压过氧化铅电极用于氯酸钠电槽试验

在电解工业中,电极材料对生产的技术经济效果有较大影响。通常人们根据导电性,耐腐蚀性,经济性和对目的反应的高效性来选择电极。因阳极容易氧化溶解,可供挑选的材料有限,所以对它的研究十分重视。钌钛阳极(DSA)的析氯电位低,又耐氯化物的腐蚀,故用于氯碱和氯酸盐电槽时,电耗低,寿命长,单槽生产能力大,但它的析氧电位较低,且不耐氧的作用,因而使用范围受到一定限制。譬如在硫酸溶液中用作析氧阳极时,寿命约为200小时。相反,陶基PbO_2电极,不仅析氧电位接近于铂,可用于高     

电积用析氧阳极的研究进展

从铅阳极合金化、金属基复合阳极和其他新型阳极三方面综述了金属电沉积中析氧阳极材料的研究现状,展望了新型析氧阳极材料的发展趋势。指出新型阳极在降低电耗、推动金属电沉积行业发展方面具有重大意义。     

Ni-Fe基析氧阳极材料的研究进展

寻找一种高效、稳定和低成本的析氧阳极材料对于在碱性环境中电解水的研究具有非常重要的实际意义。近年来,Ni-Fe基材料以其低成本及在碱性条件下具有高催化活性的特点成为析氧反应电极材料的研究热点。本文概述了近几年国内外学者对不同的Ni-Fe基析氧材料(包括Ni-Fe合金、Ni-Fe氧化物、Ni-Fe层状双金属氢氧化物及Ni-Fe基复合材料等)在合成方法、物理形态、化学结构和催化性能等方面所进行的研究,介绍了Ni-Fe基材料的析氧反应机理的进展,探究了析氧反应活性相以及Fe的掺入对Ni基氢氧化物的结构和活性的影响,最后指出了合成方法的改进及详细反应机理的探究将会成为未来Ni-Fe基析氧阳极材料的重点研究方向。     

Ru-Ti-Sn/Ti三元氧化物金属阳极的析氧性能

本文用一般电极性能测试方法考察了Ru-Ti-Sn/Ti三元氧化物涂层阳极的电极寿命和析氧活性。实验表明，与Ru-Ti/Ti、Ru-Ti-Ir/Ti氧化物阳极比较，Ru-Sn-Ti/Ti阳极具有一定的析氧活性和抗氧化作用。     

Pb-Ag-Sb-Ca合金在锌电沉积过程中阳极性能的研究

实验在72h恒电流电解过程中,通过暂稳态极化曲线测试方法,在酸性硫酸锌溶液中研究了Pb-0.3%Ag-0.6%Sb-0.06%Ca四元合金阳极的电化学性能,并分析了析氧动力学参数。结果表明,在电解过程中,阳极析氧过电位和析氧动力学参数发生很大的变化,这是因为阳极氧化层存在一个形成与稳定的过程。随着电解时间的延长,阳极材料的析氧过电位呈现不断降低的趋势,电极表面交换电流密度呈现逐渐升高的趋势。     

β-PbO_2阳极的制备及其析氧性能的研究

为了提升镍阳极析氧活性,降低氧析出过电位,通过电镀技术在室温条件下制备了不同电流密度的二氧化铅镀层阳极。采用扫描电镜和X射线衍射对镀层的表面形貌和晶体结构进行了表征。运用循环伏安(CV)和线性扫描(LSV)技术分析比较了不同电流密度条件下的二氧化铅镀层的化学性质。并测试了所制阳极的镀锌槽电压的大小。研究表明,电流密度为20m A/cm2时,镀PbO_2层效果最好,β-PbO_2电极可促进阳极析氧反应的动力学过程,降低镍基阳极的析氧电位,β-PbO_2电极可通过降低析氧电位来降低电沉积金属锌的槽电压。     

金属阳极表面活性及电化学特性评价

通过对电极析氯电位和析氧电位测定及电极极化曲线、电极强化寿命测试,评价金属阳极表面活性及电化学特性,指导金属阳极电解槽管理。     

火电厂高盐高氨氮废水电解除氨氮及制氯性能研究

通过电化学试验测定了4种钛基金属氧化物DSA阳极的析氯、析氧电位,优选了Ti/Ru O2-Ir O2(R2)电极进行高盐高氨氮废水的电解试验,研究电流密度、TDS、pH、极板清洗等因素对电解除氨氮及制氯过程的影响。试验结果表明:电流密度、极板清洗对氨氮的平均降解速率影响较大,而水样的pH、TDS的影响较小。高盐废水中氨氮的电解降解过程符合准零级反应动力学规律。     

钛基IrO2+SnO2电极的析氧性能及其在电合成丁二酸中的应用

通过热分解法制备了IrO2+ SnO2/Sb2 O3+ SnO2/Ti、IrO2+ SnO2/Ti、IrO2+ Ta2O5/Sb2O3+ SnO2/Ti电极,通过线性伏安、电化学阻抗、强化寿命测试等研究了钛基涂层电极在1 mol· L-1硫酸溶液中的析氧性能.采用EDX、SEM等考察了电极的表面元素分布和电极强化寿命测...     

涂层电极的40年

钛阳极也称DSA,是以金属钛为基体在其表面涂覆以铂族元素氧化物的一种电极材料。总结了40年来DSA在电解工业中的应用概况。对各种型号的析氯电解用DSA涂层组分及其特点进行了说明,同时,对应用于硫酸电解、铜箔制造、印刷电路基板电镀、钢板镀锌和三价铬电镀等工业中的DSA进行了介绍。指出了今后的发展方向。     

Investigation of the oxygen evolving electrode in pH-neutral electrolytes: Modelling and experiments of the RDE-cell

A model has been developed to illustrate the complex interplay between the acidifying electrode reactions for oxygen evolution, mass transport and homogeneous reactions in pH-neutral electrolytes. Modelled polarisation curves of the oxygen evolution reaction were verified by polarisation curves experimentally measured in 5 M NaClO₄ on a RDE of DSA material. The conditions in the simulations and in the experiments were similar to those in the chlorate process (high ionic strength, 70 °C, chromate-containing electrolyte, DSA electrode), in which the oxygen evolution reaction is one of the possible side reactions. The model predicted the concentration gradients of H⁺, OH⁻, CrO₄²⁻ and HCrO₄⁻ during oxygen evolution on the RDE. It was found that an important part of the chromate buffering effect at high current densities occurs in a thin (in the order of nanometers) reaction layer at the anode. From comparisons between the model and experiments, a buffering reaction has been proposed. The most likely reaction for the chromate buffering in the investigated system is CrO₄²⁻ reacting with water to HCrO₄⁻ and OH⁻. In the chlorate process, where chromate is a buffer and oxygen evolution is a side reaction, it is likely that chromate promotes oxygen evolution from OH⁻.     

An investigation of sulphite ion oxidation as an alternative anodic reaction in fluidized bed electrowinning or other high rate electrolysis cells

The oxidation of sulphite ion to sulphate ion appears to offer attractions as an anodic reaction for cells operated at high current density such as those used in the fluidized bed electrodeposition of metals. In the present investigation several anodes were tried in a cell where the anolyte was aqueous ammonium sulphite solution and copper was electrowon from acidified aqueous cupric sulphate solution onto a fluidized cathode. The cell voltage was determined as a function of current density and a porous anode consisting of reticulated vitreous carbon with a lead coating was found to yield low cell voltages as did a DSA anode. The former anode did not evolve oxygen in the current density range up to 5500 A m^–2 whereas the latter showed the onset of oxygen evolution as the current density was raised. Some effects of anolyte flow rate and extent of conversion of sulphite to sulphate, as well as the distribution of potential drops in the cell were determined. Below 3500 Am^–2, sulphite ion oxidation using the reticulated vitreous carbon anode resulted in cell voltages below those of conventional commercial cells for copper electrowinning.     

阳极涂层的研究进展

一种涂布了电催化活性金属氧化物的涂层阳极（DSA）是20世纪60年代发展起来的一种新型不溶性阳极电极。主要从基体、金属氧化物涂层以及制备工艺等方面论述了影响DSA阳极涂层性能的因素,并对其今后的发展方向作了展望。     

Sulphurous acid as anodic depolarizer in copper electrowinning Part II

The growing interest in the electrowinning of copper has lead to several modifications including anodic reactions proposed to reduce the high energy requirement. The addition of sulphurous acid to a copper sulphate electrolyte has been studied to avoid oxygen evolution at the anode which requires a potential in excess of 2V. In particular, the effect of different anode materials, concentration of sulphurous acid, current density, copper and sulphuric acid concentrations in the electrolyte have been investigated. Measurements of anode potential, cell voltage, current efficiency and energy consumption during the electrowinning of copper have been made using a diaphragm cell. It was found that graphite and lead coated with Ir–O₂ are better electrode materials than lead and DSA anodes and sulphurous acid can be used as anodic depolarizer.     

酸性氯化铜蚀刻废液电解再生用阳极的筛选

采用热分解法制备了8种DSA涂层阳极,通过循环伏安曲线、极化曲线、强化寿命等测试研究了不同涂层的电催化性能。结果表明,RuIrTiSnMn/Ti涂层阳极在酸性蚀刻废液电解再生工艺的阳极电流密度范围内具有最高的析氯电位,且强化寿命高(为538h),涂层成本最低,可作为酸性蚀刻废液电解再生工艺用的阳极。     

Evaluation of the electrochemical activity of a Ti-RuO2-TiO2 permanent anode

Most of the hydrometallurgical processes use sulphuric acid solutions. The main anodic reaction is oxygen evolution by decomposition of water. Traditional anode materials have been lead alloys that have high overpotential towards oxygen evolution. Oxide type anodes are more active but they are also more expensive. In this work, the activities of binary RuO₂-TiO₂ anodes were measured using different electrochemical techniques. The activity measurements were based on the measurement of the redox reaction between Ru(III) and Ru(IV) in cyclic voltammetry and on the oxygen evolution reaction in potentiostatic tests and galvanostatic electrochemical impedance spectroscopy. Factors related to intrinsic electrocatalytic properties and electrochemically active surface area could be separated. Above 30 mol% no significant increase in activity towards oxygen evolution is gained by increasing the concentration of active oxide. With low amount of active oxide most of the active sites are inside the pores and cracks. This will cause anode failure by bubble formation inside the anode.     

钛基金属氧化物涂层电极的研究进展

钛基金属氧化物涂层电极又称DSA,是一种新型不溶性阳极电极。综述了钛基金属氧化物涂层电极的研究进展,包括钛基钌系涂层电极、钛基铱系涂层电极、钛基二氧化锰电极和钛基二氧化铅电极。介绍了不同钛基涂层电极材料的制备方法、性能特点和应用情况,并对其今后的发展方向作了展望。     

Electrochemical oxidation of oxalate ion in the presence of fluoride ion, and radical analysis by ESR

The problem at hand is the electrochemical oxidation of oxalate ion, which is accelerated by fluoride ion at a platinum anode. The hypothesis that fluoride ion traps incipient hydroxyl radicals as hydroxyfluoride radical anions was not supported by ESR experiments in which hydroxyl radicals were generated in the presence of the spin trap α-(4-pyridyl-1-oxide) N-tert-butyl-nitrone with and without the addition of fluoride ion. The electrochemical oxidation of oxalate at constant current followed current controlled kinetics both at a platinum anode, as observed previously, and at a boron-doped diamond anode, but the rate of the latter reaction was indifferent to the presence of fluoride ion. We propose that the competition of fluoride and hydroxide ions for the Pt/PtO_n surface inhibits the dimerization reactions that lead to oxygen evolution; the displacement of oxygen evolution to more positive potentials overcomes the overpotential for the oxidation of oxalate at this anode. Fluoride ion has no influence on the oxidation of oxalate at BDD because oxygen evolution inherently occurs at more positive potentials at this anode.