Protons play a significant role in electrochemical reactions. In a simulated Volmer reaction, we can imagine the initial state as a situation where protons are in a bulk state with an empty metal slab. To study the reaction barrier, we need to move the protons from the reservoir to the surface of the electrode. We term the state where the proton has reached the near-surface layer the pseudo-initial state. This prompts the question of how protons from the bulk migrate to the near-surface and whether this pseudo-initial state truly exists. If protons don't become localized at the near-surface layer but follow a concerted mechanism, the existence of the pseudo-initial state becomes uncertain. In our research, we examined the pathways of protons in the grand canonical system using the solvated jellium method and determined the localization of protons in the near-surface layer, thus confirming the existence of pseudo-initial states.