Comparative study on the oxygen reduction reaction electrocatalytic activities of iron phthalocyanines supported on reduced graphene oxide, mesoporous carbon vesicle, and ordered mesoporous carbon

• Novel FePc/carbon catalysts for ORR are fabricated by π–π stacking interactions.
• The FePc/OMC catalyst (FePc:OMC = 2:1) exhibits the best ORR catalytic activity.
• A positive correlation between ORR catalytic activity and specific surface area.
• Low H2O2 yield and 4e− oxygen reduction process of FePc/OMC at low over potentials.
• Superior tolerance against methanol crossover and excellent stability of FePc/OMC.

Iron phthalocyanine (FePc) is combined with different carbon matrixes (reduced graphene oxide (RGO), mesoporous carbon vesicle (MCV), and ordered mesoporous carbon (OMC)) through non-covalent π–π interaction. The nitrogen adsorption–desorption isotherms display that their specific surface areas obey an order of OMC > MCV > RGO. Raman spectroscopy reveals that OMC contains the most surface active sites. Meanwhile, SEM images show that the FePc monomers are more evenly dispersed on OMC than on MCV or RGO. Electrochemical measurements also display that oxygen reduction reaction (ORR) is catalyzed more easily on the FePc/OMC than on the FePc, FePc/MCV, and FePc/RGO, undoubtedly testifying the importances of specific surface area and surface active sites of OMC matrix for uniformly dispersing FePc molecules and then improving the ORR performances. Particularly, experiment results reveal that the FePc/OMC catalyst displays an enhanced 4-electron pathway in ORR either in acid or in alkaline media. Meanwhile, the FePc/OMC also shows better durability and superior stability towards methanol crossover than the Pt/OMC catalyst in both acid and alkaline media, potentially making the FePc/OMC a non-precious metal catalyst for ORR in fuel cells.

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