Single-atom catalysts (SACs) have been deemed as one of the most prospective substitutes for high-efficiency oxygen reduction reaction (ORR) catalysts due to its theoretical maximum atomic utilization. However, the convenient preparation and the further improvement in activity of SACs are...

The four well-designed porphyrin derivatives are synthesized with different electronegativity groups at the meso-substituted phenyl groups to turn the built-in electric field of the porphyrin molecules. Among them, the meso-tetrakis(meta-hydroxyphenyl) porphyrin (mTHPP) with largest diploes is...