Electrolysis of water to produce hydrogen using proton exchange membranes (PEM) is of great interest especially if the production can be coupled to a source of renewable energy, where the renewable hydrogen cycle could be achieved. The oxygen evolution reaction (OER) takes place at the anode of a PEM water electrolyzer and it is known to be the rate-determining step in the overall electrolysis process. Therefore, the catalytic activity for the OER must be improved, which only can be accomplished with a better knowledge and understanding of the OER mechanism. In this work, density functional theory calculations are used to analyze the OER reaction pathways on RuO₂, IrO₂, and M-doped Ir oxides (with M= Ni, Co) in order to get a deeper insight of the importance of each of these stages in the water electrolysis process. The DFT studies are used to interpret and complement experimental synthesis, characterization, and electrochemical evaluation studies of novel Ir-Ni oxy-hydroxide 2-dimensional nanoframe electrocatalysts.