## 1 Introduction
Accumulated bubbles can prevent the electrolyte from accessing the active electrode surface, increasing resistance and reducing current density, while uneven bubble departures may disrupt the operational stability of the system. Parameters such as bubble nucleation frequency, departure diameter, departure dynamics, and surface properties of the electrode are being closely studied to enhance electrolysis performance [6; 7; 8; 9; 10]. In the field of enhancing electrolysis, new procedures for hydrogen evolution reaction (HER) catalysts production are being proposed [11; 12] along with several approaches for surface structure modifications [13; 14; 15; 16; 17]. The key information allowing for optimization of the electrode and entire electrolysis process down the line is an in-depth understanding of the bubble nucleation, coalescence, and departure from the surface on the microscale. In several studies, the effect of departing bubbles is considered and evaluated both in PEM and alkaline electrolysis systems, the conclusions can be applied to the cathode as well as the anode electrode [18; 19; 20; 21; 22]. Several recent studies explored hydrogen bubble growth and departure dynamics, with a focus on microscale analysis and with the use of microelectrodes. [PERSON] et al. [23] investigated hydrogen bubble dynamics during electrolysis on a platinum microelectrode by varying the electrolyte composition. Key findings include the observation that microbubble coalescence efficiency aligns with the Hofmeister series for anions, leading to distinct bubble evolution behaviors. The results highlight the critical role of the solutal Marangoniconvection, driven by anion concentration gradients. In a further study, [PERSON] et al. [24] demonstrated that hydrogen bubble detachment during electrolysis can be controlled and optimized by adjusting electrolyte composition. They have shown that microbubble coalescence efficiency, which determines whether detachment occurs randomly or as single bubbles, is strongly influenced by the electrolyte, again following the Hofmeister series for anions, and is inhibited by alkali metal cations. [PERSON] et al. [25] also explored the effect of the electrolyte concentration on single hydrogen bubble evolution dynamics at a microelectrode during electrolysis. They used different H\({}_{2}\)SO\({}_{4}\) electrolyte concentrations (0.2-1.0 M) under various applied voltages, focusing on bubble departure diameter, average current, and bubble lifetime. They found that the highest gas production at a potential of \(-6\) V was achieved at an intermediate concentration of 0.6 M. Furthermore, they proposed a force balance model incorporating the Marangoni force for single bubbles on the microelectrode surface, noting the critical role of the solutal Marangoni force beyond a certain electrolyte concentration value. Similarly, [PERSON] et al. [26] varied the electrolyte temperature and concentration to study single hydrogen bubble evolution on a microelectrode. A notable reduction in bubble departure diameter and growth time with decreasing electrical potential and increasing reaction temperature was observed. A model for estimating the bubble coverage on a microelectrode was also presented, incorporating bubble radius and current as key influencing factors. Moreover, the dominance of bubble-induced micro convection as the primary mass-transfer mechanism for gas products at high current densities was reported. Finally, the inertia-controlled bubble growth stage was found to increase the mass transfer coefficient, while the latter decreased during the growth stage controlled by chemical reactions. [PERSON] et al. [27] performed measurements using 1.2 M H\({}_{2}\)SO\({}_{4}\) with ethylene glycol added as a surfactant and found that under the influence of electrode adsorption, the departure diameter of the hydrogen bubble is independent of the current density, but the bubble departure frequency increases with the increase in current density.