<i>Meso</i>‐substituted Metalloporphyrin‐based Composites for Electrocatalytic Oxygen Reduction Reactions

Metalloporphyrins have been regarded as one of the most promising electrocatalysts for oxygen reduction reactions (ORRs) due to their ease structure modification and robust coordinated M−N4 environment. However, electrocatalytic activity, selectivity stability metalloporphyrin-based composite catalysts are often reported be much poorer than those Pt-based materials, arousing researchers devote exploring a thorough understanding relationship between catalyst structures ORR performance/mechanisms. Here we will review design meso-positioned porphyrin from aspects selection central metal ion species in both monometallic bimetallic molecules, modulation peripheral functional substituents introduce beneficial effects, including electron affinity, steric interfacial charge states proton management. Influences different carbon materials support well electrolytes on properties briefly illustrated before presenting perspectives insights future works conclusion remarks. We hope that this Review serve roadmap advancing molecular structural substrate morphological factors impacting with ultimate goal developing improving novel metalloporphyrins efficient durable champion precious Pt/C.