The development of H2-O2 fuel cell technology is an important strategy to solve the current energy problem. The catalytic efficiency of oxygen reduction reaction (ORR) on the cathode of fuel cell is a key factor that affects the overall energy conversion efficiency. Inspired by cytochrome c oxidases (CcOs) in nature, the researchers have studied many metal macrocyclic porphyrin complexes as ORR catalysts which show excellent electrocatalytic activity for ORR. This review addresses the current status of metal porphyrins in ORR, including the effects of meso- and β-substituents, axial ligands, second coordination spheres, binuclear metal, different metal centers, and carbon-based materials on the catalytic activity and selectivity of ORR. Furthermore, the future research direction of metal porphyrin catalysts is also predicted.
