Composite lead dioxide electrode and preparation method thereof

Abstract

The invention relates to the technical field of electrodes, in particular to a composite lead dioxide electrode and a preparation method thereof. The composite lead dioxide electrode comprises a composite layer, and the composite layer is composed of the following raw materials in parts by weight: 10%-40% of lead dioxide powder, 58%-88% of lead powder paste and 0.5%-2% of antioxidant. The preparation method comprises the following preparation steps: preparation of a matrix, collection of anode mud, cleaning of the anode mud, shaping of lead dioxide powder, compression molding, product shaping,anode service life testing and chloride ion resistance testing. The composite lead dioxide electrode is long in service life and high in stability, a compact lead dioxide layer is formed when the composite lead dioxide electrode is used due to the fact that the lead dioxide powder is inserted into the metal lead, the corrosion mechanism is dissolution, the corrosion speed is low, the service lifeis long, and in the high-current-density electrolysis process, the electrode of the present invention can be stably used for a long period of time.

Description

technical field [0001] The invention relates to the technical field of electrodes, in particular to a composite lead dioxide electrode and a preparation method thereof. Background technique [0002] As we all know, lead oxide-plated metal electrodes are suitable for electrolysis electrodes that require corrosion resistance or high oxygen overvoltage, such as electrolysis for oxygen generation, anodic oxidation, electroplating, electrolysis of organic materials, electrolytic treatment of wastewater, etc., and in this electrode Many improvements have been made. However, the industrial application of these electrodes has left room for improvement due to some practical problems. There are two types of lead oxide used for such electrodes, namely, orthorhombic α-PbO 2 Tetragonal β-PbO with titanium type (rutile) structure 2 . Although in α-PbO 2 When used as an electrolytic anode, its corrosion resistance is better than that of β-PbO 2 Poor, but when α-PbO is produced electr...

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Problems solved by technology

However, these methods require large amounts of expensive precious metals, so are impractical, and moreover, involve the application of complex processes

[0005] Among these methods, the method of disposing an interlayer containing platinum group metals or their oxides is impractical because the interlayer itself is extremely expensive

In addition, some of these materials are usually used as active materials for electrodes because they have lower oxygen overvoltages than lead oxides when used as anodes. If the electrolyte invades the pinholes of the lead oxide plating, etc., then due to the The electrolysis of the intermediate layer is equivalent to the anode of the gas, which may cause the peeling and destruction of the lead oxide layer. In addition, in the method of configuring the intermediate layer without platinum group metals (such as the intermediate layer of semiconductor materials of tin and antimony compounds) , although it is less likely that the intermediate layer will act as an anode, the lack of conductivity creates power supply problems

Moreover, since Pb 4+ (6-position coordination) lead ion radius is 0.78, and Sn 4+ 0.69 or with Ti 4+ Compared with 0.61A, its ionic radius is larger, so it is difficult to make the intermediate layer and the lead oxide layer firmly bond with each other by melting or forming a solid solution

Moreover, because β-PbO 2 layer has a large ionic radius as mentioned above, so in β-PbO 2 There is a lot of stress in the layer, β-PbO 2 are titanium-type oxides and are more difficult to bond intact to the interlayer

[0006] In summary, due to the properties and manufacture of lead oxide, the known lead oxide plated electrodes involve various problems and have practically not been able to obtain good electrodes.

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