Regulating the Spin State of Fe III Enhances the Magnetic Effect of the Molecular Catalysis Mechanism Aqueous-phase oxygen evolution reaction (OER) is the bottleneck of water splitting. The formation of the O–O bond involves the generation of paramagnetic oxygen molecules from the diamagnetic hydroxides. The spin configurations might play an important role in aqueous-phase molecular electrocatalysis. However, spintronic electrocatalysis is almost an uncultivated land for the exploration of the ...