Unveiling the potential of tailored β-substituted iron-porphyrins for highly efficient oxygen reduction reactions (ORR)

transfer pathway. Electron-withdrawing β-substituents combined with steric effects enhance ORR performance, with the phenyl-substituted porphyrin exhibiting unique catalytic behavior due to steric distortions in the porphyrin ring. DFT calculations revealed that a reduced HOMO-LUMO gap facilitates electron transfer which in turn improves catalytic efficiency.