Experimental Investigation of Two-Phase Electrolysis Processes

Abstract

During two-phase electrolysis for the production of oxygen and hydrogen, it is generally observed production of bubbles at one or two electrodes which indicates a change in electrical and hydrodynamic properties of the electrolyser. In the presence of gravity, the production of bubbles at the electrodes induces a macro-convection in the electrolyser. This leads to a variable distribution of the bubbles void fraction and of the current density j at the electrodes. The absence of gravity eliminates the natural convection and by the same frictional forces. The electrolysis is performed using a potentiostat. The formation of gas bubbles at the anode is observed by two cameras. The aim of this study is to predict the evolution laws of the electrochemical cell voltage and of the bubble diameter during a two-phase electrolysis depending on the two presently explored inputs: current density and gravity.