The catalytic Oxygen evolution reaction (OER) using Pt-doped graphene is highly efficient due to its exothermic nature (ΔH<0), which drives the reaction thermodynamically . In an exothermic OER, energy is released as oxo-radicals (O * ) are reduced and combine to form molecular oxygen (O2), making the process spontaneous under standard conditions. The negative enthalpy change indicates that Pt-doped graphene provides a favorable surface for adsorbing hydrogen intermediates, lowering the energy barrier for the reaction . This efficient energy transfer enables stable intermolecular interaction on the catalyst surface, which facilitates the reduction of protons and promotes the recombination of adsorbed oxygen (Oads) into molecular oxygen.