Bubble Over Potential During Two Phase A

During two-phase water electrolysis, the production of bubbles at one or both electrodes significantly alters the electrical and hydrodynamic properties of the electrolyser. This study investigates the impact of gravity on bubble formation and macro-convection, which affects the local gas void fraction and current density at the electrodes. The absence of gravity eliminates natural convection and buoyancy, leading to reduced frictional forces. The objective of this research is to quantitatively describe the evolution of the electrochemical cell potential, bubble diameter, and population density during alkaline (NaOH) electrolysis as a function of current density and gravitational effects. Four cameras were employed to observe bubble formation at the anode during experiments. Findings reveal clear relationships between these parameters, offering insights into the mechanics of bubble-related over-potentials. This work adds to the limited literature on two-phase electrolysis, emphasizing its significance in industrial processes like hydrogen production. Understanding these interactions can enhance the efficiency and design of electrolytic systems under varying operational conditions.