Electrolyte spraying within H2 bubbles during water electrolysis

Publikation: Vorabdruck/Dokumentation/BerichtVorabdruck (Preprint)

Beitragende

  • Aleksandr Bashkatov - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR), University of Twente (Autor:in)
  • Florian Bürkle - , Professur für Mess- und Sensorsystemtechnik (Autor:in)
  • Çayan Demirkır - , University of Twente (Autor:in)
  • Wei Ding - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)
  • Vatsal Sanjay - , University of Twente (Autor:in)
  • Alexander Babich - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)
  • Xuegeng Yang - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)
  • Gerd Mutschke - , Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)
  • Jürgen Czarske - , Professur für Mess- und Sensorsystemtechnik (Autor:in)
  • Detlef Lohse - , University of Twente, Max Planck Institute for Dynamics and Self-Organization (Autor:in)
  • Dominik Krug - , University of Twente (Autor:in)
  • Lars Büttner - , Professur für Mess- und Sensorsystemtechnik (Autor:in)
  • Kerstin Eckert - , Professur für Transportprozesse an Grenzflächen (gB HZDR), Helmholtz-Zentrum Dresden-Rossendorf (HZDR) (Autor:in)

Abstract

Electrolytically generated gas bubbles can significantly hamper the overall electrolysis efficiency. Therefore it is crucial to understand their dynamics in order to optimise water electrolyzer systems. Here we demonstrate a distinct transport mechanism where coalescence with microbubbles drives electrolyte droplets, resulting from the fragmentation of the Worthington jet, into the gas phase during hydrogen evolution reaction, both in normal and microgravity environments. This indicates that the H$_2$ bubble is not only composed of hydrogen gas and vapor but also includes electrolyte fractions. Reminiscent of bursting bubbles on a liquid-gas interface, this behavior results in a flow inside the bubble, which is further affected by Marangoni convection at the gas-electrolyte interface, highlighting interface mobility. In the case of electrode-attached bubbles, the sprayed droplets form electrolyte puddles at the bubble-electrode contact area, affecting the dynamics near the three-phase contact line and favoring bubble detachment from the electrode. The results of this work unravel important insights into the physicochemical aspects of electrolytic gas bubbles, integral for optimizing gas-evolving electrochemical systems. Besides, our findings are essential for studying the limits of jet formation and rupture relevant to acid mist formation in electrowinning, generation of sea spray aerosols, impact of droplets on liquid surfaces, etc.

Details

OriginalspracheEnglisch
Seiten1-12
PublikationsstatusVeröffentlicht - 31 Aug. 2024
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Schlagworte

Schlagwörter

  • physics.flu-dyn, physics.chem-ph