Collect. Czech. Chem. Commun. 1983, 48, 394-407

Oxygen cathodes based on carbon promoted with silver. I. Some electrochemical parameters of the electrodes

Miroslava Musilováa, Martin Wedellb, Jiří Mrhaa and Karel Smrčekb

a J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 102 00 Prague 2
b CKD Semiconductors, 140 03 Prague 4


A comparison of the electrochemical parameters of oxygen gas diffusion electrodes made of teflonized carbon black ( the hydrophobic component) and of a catalyst - consisting either of pure silver or silver promoted active carbon (the hydrophilic component) - enabled to investigate the influence of the silver presence in this type of electrodes. The characteristics obtained with the pure and air oxygen permitted, in combination with other measurements, to explain the role of the silver catalyst. It was found that this catalyst has a positive effect on the electroreduction of oxygen but that it also, due to its structural properties, influences in a negative way the distribution of the gas and electrolyte filled pores - which, in consequence, leads to gas transport problems in the active layer. Comparative measurements, carried out with electrodes on the silver-teflon basis have supported the assumption that both the above types of pores influence the transport processes in the active layer. The measurements showed also the advantages of the silver-teflon electrodes with pure oxygen, as well as, their disadvantages when air oxygen was used.