Hydrogen Production by Alkaline Electrolysis: Surface and Electrochemical Investigations of Materials for Diaphragms

Production of hydrogen using high pressure alkaline electrolysis is well established and allows obtaining high purity pressurised hydrogen and oxygen gases. The electrolyser's efficiency depends significantly on the ion-conductivity of diaphragms/membranes separating oxygen and hydrogen. Currently used diaphragms are made of asbestos, which are not only prohibited by recent health regulations, but also require high energy consumption. Therefore, we are looking for a new material to substitute asbestos which has an equal or even better performance. High gas purity, i.e., low gas penetration, is achieved through the small size of pores which is smaller than the hydrogen and oxygen bubbles. High ionic conductivity in asbestos is mainly achieved through its excellent wettability, the effects related to the fibrous structure and the specific porosity. The aforementioned properties most probably with the interplay of surface processes influence the ion conductivity. We report our first results of X-ray photoelectron spectroscopic study of pristine and reacted asbestos diaphragms and olivine mineral (Mg2SiO4) in 25% KOH at ambient conditions. The data combined with impedance measurements and tests in the electrolysis cell will allow the evaluation of new possibilities materials for new diaphragms.
+ ID der Publikation: hslu_101797 + Art des Beitrages: Präsentation Konferenzpapier/Tagungsbeitrag + Sprache: Englisch + Letzte Aktualisierung: 2024-07-30 12:30:09