The S-Doped Cobalt Porphyrin-Based Molecular Catalysts with Large Conjugated Meso-Substituents for Enhanced Electrocatalytic Oxygen Reduction and Evolution Reaction

摘要

Metalloporphyrin based catalysts with high activities for oxygen electrocatalysis had been prepared by non-covalent immobilization of prefabricated metalloporphyrin molecules and carbon supports. The delocalization effect of metalloporphyrins on the ORR and OER activities had been investigated experimentally and theoretically by using transition metal (Fe, Co, Ni) tetra(4-thiophenephenyl) porphyrin (M-TThP), M tetra(thienyl)porphyrin (M-TTP) and M tetra(phenyl)porphyrin (M-TPP). The results showed that Co complexes with S-doped large-conjugated framework was beneficial for 4e(-) ORR and exhibited better OER performance. Furthermore, the oxygen electrocatalytic activity differences in prepared metalloporphyrins had been rationalized by the pi-pi interactions between the metalloporphyrin and carbon black. This work demonstrates the delocalization of meso-substituents in metalloporphyrins plays a vital role in both oxygen electrocatalysis for these materials and the well-designed metalloporphyrin molecular catalysts are promising candidates for energy storage technology.

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