Chlor-alkali electrolysis with a zero-gap type oxygen cathode

A new type of oxygen gas diffusion cathode (DCP(TM)), which is placed onto an ion exchange membrane (the so-called, zero-gap type), was proposed and tested in a chloralkali cell. The cell performance was measured under various electrolytic conditions, such as temperature and concentration of the electrolyte as well as current density. By optimizing the components and the structure of the electrode, the cell voltage attained 2.05 V at 30 A/dm(2), which corresponds to a reduction of about 1 V vs. a conventional hydrogen evolution cathode. The cell has been operated stably over 700 days.