An Efficient Bio‐inspired Oxygen Reduction Reaction Catalyst: MnO x Nanosheets Incorporated Iron Phthalocyanine Functionalized Graphene

Oxygen reduction reaction (ORR) catalysts play a critical role in energy storage and conversion devices and have been attracted enormous interests, and however, it remains challenging to develop highly active cheap catalysts in a simple and green route. Inspired by the heme‐copper oxidases (HOCs), in which the ORR active center is originated from the incorporation of Fe‐N 4 with copper atom, we here developed a fine manganese oxide nanosheets (MnO x NSs) integrated with iron phthalocyanine (FePc) anchored on highly conductive graphene (MnO x /FePc‐G) through a green route only involve ethanol as the reagent. The bio‐inspired catalyst MnO x /FePc‐G demonstrated high ORR activity with a half‐wave potential ( E 1/2 ) of 0.887 V, about 57 mV more positive than that of Pt/C. And the current density ( j ) at 0.9 V is about 1.9 mA cm −2 , which is three times of Pt/C and FePc‐G. More importantly, the bio‐inspired systems show superior stability in comparison to commercial Pt/C, showing a potential of 0.863 V to deliver a j of 3 mA cm −2 after 18 000 s polarization, about 80 mV higher than that of 0.783 V for Pt/C. The high activity is contributed by the integration of the FePc and MnO x NSs that plays the role to assist the cleavage of the O 2 bond. Our approach provides a new evidence to develop highly efficient ORR catalysts through imitate the naturally involved systems through a simple route.