Studies of the corrosion and the catalytic activity of tungsten carbide, synthesized from the white modification of tungstic acid by carburization in CO at low temperature (700 "C) in phosphoric acid are reported. Oxidation of the surface and partial dissolution of the catalyst, as well as alteratio
Activity and corrosion of tungsten carbide recombination electrodes during lead/acid battery operation
โ Scribed by I. Nikolov; G. Papazov; V. Naidenov
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 556 KB
- Volume
- 40
- Category
- Article
- ISSN
- 0378-7753
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โฆ Synopsis
The oxidation of the tungsten carbide (WC) catalyst in recombination electrodes partially immersed in H,S04 solution was investigated when the electrodes operated in an atmosphere of oxygen and hydrogen.
It has been established that after a long operation period (4000 h) 60 to 70% of the catalysts, depending on the initial active surface of WC, may be oxidized to WO,, whereby the rate of recombination decreases about three times. It is assumed that the oxidation of WC is due to the HzOz formed as an intermediate product of the recombination of hydrogen and oxygen. Silver accelerates the decomposition of Hz02 and hence the use of a WC-Ag mixture as catalyst in the recombination electrodes reduces strongly the carbide corrosion.
๐ SIMILAR VOLUMES
Sedimented electrodes were used for the investigation of the changes in the catalytic activity during corrosion in 4.5 and 9.9N HsS04 of tungsten carbides synthesized under different conditions.1 It is shown that during corrosion the specific activity of all the samples #udied reaches a maximum afte