Surely, you can say that "OER is the extraction of oxygen available in water in a molecular form." On the other hand, OER is water oxidation reaction, which is the 4-electron and multi-step thermodynalically very unfavorable process. Why are you surprised that this is a slow reaction?
Yurii V Geletii ...Sir, I am not surprise but trying to have a grasp on its technical aspects to get a clear understanding of OER. Because I cannot go by memorizing this thing. Could you please share any relevant material to have a clear understanding of this process, please?