On the effect of various active carbon catalysts on the behaviour of carbon gas-diffusion air electrodes: 2. Acid solutions

✍ Scribed by J. Mrha; I. Iliev; A. Kaisheva; S. Gamburzev; M. Musilova

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 344 KB
• Volume: 1
• Category: Article
• ISSN: 0378-7753
• DOI: 10.1016/0378-7753(76)80005-5

✦ Synopsis

The electrochemical performance of carbon gas~liffusion air electrodes was studied in acid solutions. Electrodes with defined structure prepared from 11 different active carbon samples were investigated when working with air and oxygen. The catalytic activity of these samples both in acid and in alkaline solutions was compared. The extent of mass transport hindrances was estimated in terms of AE(i) curves. The effect of platinum and polymeric phthalocyanine's as promotors on the overall electrochemical characteristics of oxygen and air electrodes was studied. In the case of oxygen electrodes at E = 700 mV (vs. RHE) 120 mA/cm 2 were obtained with NORIT NK active carbon promoted with 2.36 mg p!atinum/cm 2 and 30 mA/cm 2 with P-33-active carbon promoted with 13 mg iron phthalocyanine/cm 2 . At low current loads the AE(i) curves and the slopes of the linear portion of the E vs. log i curves of oxygen electrodes reflect a different electrochemical mechanism and a different rate of mass transport for pure active carbon and active carbon promoted with the above-mentioned catalysts.