@article{GrimmigGillemotStuckietal.2022,
  author    = {Grimmig, Roman and Gillemot, Philipp and Stucki, Samuel and G{\"u}nther, Klaus and Baltruschat, Helmut and Witzleben, Steffen},
  title     = {Operating an ozone-evolving PEM electrolyser in tap water: A case study of water and ion transport},
  journal   = {Separation and Purification Technology},
  volume    = {292},
  issn      = {1383-5866},
  doi       = {10.1016/j.seppur.2022.121063},
  institution = {Fachbereich Angewandte Naturwissenschaften},
  pages     = {121063},
  year      = {2022},
  abstract  = {While PEM water electrolysis could be a favourable technique for in situ sanitization with ozone, its application is mainly limited to the use of ultrapure water to achieve a sufficient long-time stability. As additional charge carriers influence the occurring transport phenomena, we investigated the impact of different feed water qualities on the performance of a PEM tap water electrolyser for ozone evolution. The permeation of water and the four most abundant cations (Na+, K+, Ca2+, Mg2+) is characterised during stand-by and powered operation at different charge densities to quantify underlying transport mechanisms. Water transport is shown to linearly increase with the applied current (95 ± 2 mmol A-1 h-1) and occurs decoupled from ion permeation. A limitation of ion permeation is given by the transfer of ions in water to the anode/PEM interface. The unstabilized operation of a PEM electrolyser in tap water leads to a pH gradient which promotes the formation of magnesium and calcium carbonates and hydroxides on the cathode surface. The introduction of a novel auxiliary cathode in the anolytic compartment has shown to suppress ion permeation by close to 20\%.},
  language  = {en}
}