Polymer electrolyte membrane electrolyser

Electrolysis uses electricity to split water into its basic components (H2 and O2). Polymer electrolyte membrane (PEM) electrolysers use a proton conducting solid polymer electrolyte (SPE) for the assembly of the electrolysis cell and separation of H2 and O2 evolution reactions separately on cathode and anode sides. While it is currently one of the two commercially matured technology together with alkaline electrolysers, its cost-reduction potential is considerably larger while presenting other advantages such as higher flexibility, higher operating pressure (lower need for compression), smaller footprint (relevant for coupling with offshore wind), faster response and lower degradation rate with load changes. PEM electrolysers need, however, expensive electrode catalysts (platinum, iridium) and membrane materials. Currently, the lifetime of PEM and Alkaline is similar.
There is a lot of research done in the direction of new acid stable electrolysers, that could enable the development into usable technologies in the near future, further reducing PEM electrolyser costs, and increasing lifetimes.