Mass transfer at gas evolving electrodes

✍ Scribed by L.J.J. Janssen

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 598 KB
• Volume: 23
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(78)80101-7

✦ Synopsis

To elucidate the mechanism af the mass transfer at a gas evolving electrode, the thickness of the diffusion layer 6 has been determined as a function of the volume rate of the gas evolution u, for both hydrogen and oxygen evolving electrodes in alkaline solution. The effect of electrode material, alkaline concentration, roughness, position and disk diameter of the electrode, gas pressure and of temperature upon the 6/v relation is given. A low absolute value of the slope of the log a/log u, of about 0.3 is found experimentally when no coalescence of gas bubbles occurs and a high one, that is about 0.9 when coalescence occurs frequently. It has been concluded from the experimental results that the mass transfer can be explained on the basis of the hydrodynamic model when no coalescence of gas bubbles occurs and on that of the penetration model when coalescence occurs frequently.