In situ characterisation of PEM water electrolysers using a novel reference electrode

Edward Brightman, James Dodwell, Nick van Dijk, Gareth Hinds

Research output: Contribution to journalArticlepeer-review

54 Citations (Scopus)


Polymer electrolyte membrane water electrolysers (PEMWEs) are a promising technology for hydrogen production but catalyst degradation mechanisms are poorly understood, hampering informed catalyst design for extended lifetimes and the use of more economical loadings. Herewe demonstrate the application of an innovative reference electrode to the study of catalyst degradation in an operating PEMWE. This approach enables separation of the relative contribution of anode and cathode to the overall water splitting reaction. It is shown that, in shut-down periods during power cycling, the cathode contributesmore to changes in open circuit voltage than the anode. Changes in the electrochemical surface area of the platinum cathode as a result of power cycling are measured in situ for the first time using hydrogen underpotential cyclic voltammetry. The results demonstrate that degradation of the platinum cathode plays a more significant role than conventionally assumed by the electrolyser community, which has tended to focus more on the iridium/ruthenium oxide anode because it dominates the performance of the cell.

Original languageEnglish
Pages (from-to)1-4
Number of pages4
JournalElectrochemistry Communications
Early online date13 Jan 2015
Publication statusPublished - 31 Mar 2015


  • accelerated degradation
  • electrolyser
  • polymer electrolyte membrane water electrolysers (PEMWE)
  • reference electrode
  • PEM water electrolyser
  • catalyst degradation mechanisms


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