A step forward in the direct electrolysis of sea water
February 1, 2023
Unfortunately, the electrolysers on the market require fresh water which is rather scarce considering the traditional needs which are primary. On the contrary, sea water is available in practically inexhaustible quantities and therefore could be the solution. The first alternative consists in desalination of sea water in order to be able to use the electrolysers already available. The alternative is the construction of new electrolysers that are able to use sea water directly.
In an article published on Nature, a group of researchers from the University of Adelaide (Australia) reported the results of the experimentation carried out on an electrolyser of this type, obtaining stable operation for over 100 h at a current density of 500 mA cm− 2 with performance similar to that of a typical PEM electrolyser operating in high purity water.
Success has been achieved due to the introduction of a Lewis acid layer (for example, Cr2O3) on transition metal oxide catalysts. The local alkalinity generated in situ facilitates the kinetics of both electrode reactions and avoids the attack of chlorides and the formation of precipitates on the electrodes.