Albeit the ionic-specific effects known in the context of Hoffmeister series certainly can play a role in experimental systems, we emphasize that in our simulations the only difference between Co 2+ and Na + ions is their charge, while all the other interactions are kept the same. Therefore, our simulations clearly show that a change in the valency alone is sufficient to ensure preferential accumulation of multivalent ions in the PEC phase, yielding an almost quantitative agreement with the experiments.