NiFe2O4隋性阳极的制备及其电解腐蚀机理

以Fe2O3和NiO为主要原料，添加2％（按质量计）MnO2，采用固相烧结工艺制备了NiFe2O4惰性阳极。用X射线衍射和扫描电子显微镜对材料的组成和微观结构进行了研究，测量了样品在冰晶石熔盐中不同电流密度下的电解腐蚀速率，并对其腐蚀机理作了初步探讨。结果表明：惰性阳极由NiO和NiFe2O4尖晶石两相组成，MnO2作为固溶体在尖晶石晶界处富集。电解腐蚀呈现出物理化学溶解过程，熔盐对试样的电解腐蚀首先要在晶界处发生反应生成更稳定的FeAl2O4相，而FeAl2O4相结构致密，冰晶石熔盐通过该相向NiFe2O4尖晶石晶粒内扩散速度减慢，从而降低了腐蚀速率。     

钛基复合铂电极的制备和在过硫酸铵生产中的试用

分别用电镀法、爆炸法、电阻焊接法制备了三种钛基复合铂电极,并在电解法过硫酸铵生产作阳极挂槽进行电解运转试用,同时考察了这三种电极的使用寿命及使用效果。试用结果表明用电阻焊接法制备的钛包铂电极使用效果最理想,与传统的铝基铂电极相比,使用寿命长,可节约14%的能耗。     

3,4-二甲基苯甲醛的合成研究进展

对合成3,4-二甲基苯甲醛的各种方法进行了综述,并指出其研究进展和存在的问题。     

催化铁内电解法预处理硝基苯废水

在传统的铁炭内电解反应器中加入铜,对硝基苯废水进行预处理,可以使废水中的硝基苯转化为苯胺,从而提高废水的可生化性。结果表明,在中性和弱碱性条件下,催化铁内电解法对硝基苯废水的处理效果明显优于铁屑内电解法。本文还研究了催化内电解法的影响因素。     

氧化铝陶瓷基板工艺研究

本文主要介绍了流延法生产氧化铝陶瓷基板的工艺.研究了原料粒度分布对基板微观结构的影响,用流延法制备了96%氧化铝陶瓷基板,并对基板表面被釉,试验了基板的性能,研究了基板生产过程中一些关键的因素.     

铝-氮化铝结合刚玉质滑板的抗氧化性能

研究了铝-氮化铝结合滑板在氧化气氛下加热升温过程中质量的连续变化特征,以及氧化前后试样的外形尺寸和强度的变化,通过热力学计算和动力学分析得知,试样在氧化过程中表现出的质量变化特性,有助于其组织结构的致密,特别是金属铝的氧化使得其在高温下形成氧化隔离层,提高了滑板的抗侵蚀能力和抗渗透能力。     

硫酸锰电解槽中垢物清除剂的研制与应用

为有效清除硫酸锰电解液电解锰时在加热管外壁上所产生的难溶垢物,在室内分析实验的基础上,研制出以JCS-2解膏剂为主要成分的垢物清除剂。该清除剂性能可靠．经济合理、施工方便,可满足实际生产要求。     

AlN陶瓷的烧结致密化与导热性能

氮化铝陶瓷具有高热导率、低介电常数、与硅相匹配的热膨胀系数等优良特性,应用领域非常广泛。对A l N粉体的合成、烧结工艺、助烧结剂及其应用等方面进行了介绍,并对A l N未来的发展趋势进行了展望。     

Electrochemical formation of AlN in molten LiCl-KCl-Li3N systems

Electrochemical formation of aluminum nitride was investigated in molten LiCl-KCl-Li₃N systems at 723 K. When Al was anodically polarized at 1.0 V (versus Li⁺/Li), oxidation of nitride ions proceeded to form adsorbed nitrogen atoms, which reacted with the surface to form AlN film. The obtained nitrided film had a thickness of sub-micron order. The obtained nitrided layer consisted of two regions; the outer layer involving AlN and aluminum oxynitride and the inner layer involving metallic Al and AlN. When Al electrode was anodically polarized at 2.0 V, anodic dissolution of Al electrode occurred to give aluminum ions, which reacted with nitride ions in the melt to produce AlN particles (1-5 μm of diameter) of wurtzite structure.     

Electrochemical study of a hydrogen diffusion anode-membrane assembly for membrane electrolysis

The membrane electrode assembly (MEA) studied was constituted with a gas diffusion electrode (E-TEK) impregnated with Nafion^® solution which was assembled with a Nafion^® 117 cation exchange membrane under heat and pressure. The MEA was used as anode in a membrane electrolysis (ME) cell with the objective to regenerate HCl and NaOH from NaCl. Current efficiency for hydrogen oxidation was determined and its value is 100%, which indicates that the only reaction occurring at the anode is the oxidation of hydrogen. Current-potential curves, recorded in different conditions, showed a linear variation in the range 0-3000 A m⁻² when hydrochloric acid concentration is below 2 mol dm⁻³. In this case, the overvoltage was shown to be mainly due to the ohmic drop in the membrane and in the layer where Nafion^® impregnation was performed. MEA overvoltage necessary to reach 3000 A m⁻² current density was about 0.12 V. For high HCl concentration (6-8 mol dm⁻³), the MEA overvoltage increased sharply with current density due to the adsorption of chloride anions on platinum catalyst.