Oxygen Generation by a Novel Electrochemical Method

Abstract

The present oxygen generating apparatus comprises as the cathode a porous air diffusion electrode commonly employed in fuel cells, while the anode consists of a nickel plate. When air is supplied to the cathode, the oxygen contained is reduced to OH^- ion and transported through the electrolyte to the anode, where it is recovered as oxygen gas. In this process, the single electrode potential at the anode is of the same value as in the case of electrolysis of water. On the other hand, however, the cathode potential for reducing O₂ to OH^- is nobler than that for reducing H⁺ to H₂ in water electrolysis. Consequently the overall potential between the electrodes takes a lower value than in the electrolytic process. The experiments lead to the conclusion that the power consumption is of the order of 2 KWH/M³ of O₂ obtained, approximately one fifth of what is normally required in the electrolytic process. With further improvements in air diffusion electrodes, one may expect that the power consumption is substantially lowered to such an extent that the conventional fractionating process of air becomes obsolete.