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Directional Construction of Low-Coordination Fe–N3 Coupled with Intrinsic Carbon Defects for High-Efficiency Oxygen Reduction

MetadataDetails
Publication Date2024-08-21
JournalACS Nano
AuthorsXinrui Li, Guanying Ye, Weiwei Zhu, Min Tian, Ruiting Wang
InstitutionsCentral South University
Citations24

Regulating the coordination environment of Fe-N<sub><i>x</i></sub> sites is an efficient but challenging approach for promoting the intrinsic catalytic activity of single-atom Fe/N-codoped carbon (Fe-N-C) toward the oxygen reduction reaction (ORR). Herein, low-coordination Fe-N<sub>3</sub> sites coupled with carbon vacancies (Fe-N<sub>3</sub>/C<sub>V</sub>) are directionally constructed in Fe-N-C via pyrolysis of a metal-organic framework (MOF) precursor with N<sub>3</sub>-Zn-O-Fe moieties, which are delicately prefabricated by chemically anchoring Fe<sup>3+</sup> onto a H<sub>2</sub>O-etching induced linker-missing Zn-N<sub>3</sub> site in the MOF precursor. The optimized Fe-N-C with the Fe-N<sub>3</sub>/C<sub>V</sub> sites displays a high ORR half-wave potential of 0.92 V (vs RHE), which is attributed to the optimized electronic structure and binding strengths of the active Fe center toward the ORR intermediates stemming from the synergy of the asymmetric configuration of Fe-N<sub>3</sub> as well as the adjacent carbon vacancies. This work could be enlightening for the design and construction of high-activity coupling sites in metal and nitrogen-codoped carbon catalysts.