Corrosion resistance and catalytic activity of tungsten carbide in phosphoric acid

✍ Scribed by V. Nikolova; I. Nikolov; T. Vitanov; L. Yotova

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 1010 KB
• Volume: 12
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/0378-7753(84)80009-9

✦ Synopsis

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 alterations of the specific surface and catalytic activity, were observed at 20 "C. Carbides with smaller initial specific surfaces were found to retain their catalytic activity for a longer period of time.

The corrosion rate of gas diffusion electrodes, catalysed with tungsten carbide was found to be substantial during operation at 150 "C and with current densities of 50 mA cmw2 in a hydrogen atmosphere. These electrodes displayed stable operation during the initial 200 -220 h, but then their polarization increased. The possible reasons for such behaviour are discussed.