The study investigates the impact of intrinsic magnetic order on the electrochemical water splitting reaction, specifically focusing on the oxygen evolution reaction (OER). The researchers used epitaxial La0.67Sr0.33MnO3 thin films as model catalysts, tuning their magnetic order from ferromagnetic to paramagnetic by changing the temperature in situ during water electrolysis. They found that ferromagnetic ordering below the Curie temperature enhances OER activity. Additionally, they observed a slight current density enhancement when an external magnetic field was applied, with the dependence of this enhancement correlating with the magnetic anisotropy in the catalyst film. The lack of long-range magnetic order at the catalytic surface suggests that the OER enhancement is related to the magnetic order of the bulk catalyst. The findings suggest that both the intrinsic magnetic order and magnetic domain alignment in La0.67Sr0.33MnO3 films increase their catalytic activity. The study proposes a unifying picture for the spin-polarized enhancement in magnetic oxide catalysts, integrating the effects of intrinsic magnetic order, domain alignment, and external magnetic fields.The study investigates the impact of intrinsic magnetic order on the electrochemical water splitting reaction, specifically focusing on the oxygen evolution reaction (OER). The researchers used epitaxial La0.67Sr0.33MnO3 thin films as model catalysts, tuning their magnetic order from ferromagnetic to paramagnetic by changing the temperature in situ during water electrolysis. They found that ferromagnetic ordering below the Curie temperature enhances OER activity. Additionally, they observed a slight current density enhancement when an external magnetic field was applied, with the dependence of this enhancement correlating with the magnetic anisotropy in the catalyst film. The lack of long-range magnetic order at the catalytic surface suggests that the OER enhancement is related to the magnetic order of the bulk catalyst. The findings suggest that both the intrinsic magnetic order and magnetic domain alignment in La0.67Sr0.33MnO3 films increase their catalytic activity. The study proposes a unifying picture for the spin-polarized enhancement in magnetic oxide catalysts, integrating the effects of intrinsic magnetic order, domain alignment, and external magnetic fields.