This study investigates the complex dynamics of the oxygen-evolution reaction (OER) in systems involving Ni(Fe) (hydr)oxides and the iron coordination compound Fe phthalocyanine-4,4',4",4‴-tetrasulfonate. It offers a novel perspective on the interaction between nickel hydroxide and the Fe compound during the OER process. The Fe complex facilitates the controlled release of trace Fe ions into the Ni (hydr)oxides as it undergoes degradation or demetalation within the Ni(II)/(III) potential range. Once the electrode surface reaches saturation with Fe, additional contributions from Fe have minimal impact on OER activity, and the turnover frequency rapidly reaches its maximum value (approximately 1 s